Z-Vent Stainless Steel Venting for Marey 5L, 10L & 16L Tankless Water Heaters

Globaltowne is a supplier of Z-Flex Stainless Steel Venting material and carries a large variety of sizes ranging from 3" - 24" single wall stainless Steel venting.  Globaltowne can also get 3" - 24" diameter double wall stainless steel venting.  Marey Gas Tankless Water Heaters come in 3 different sizes from a small 5 Liter gas tankless, a 10 Liter gas tankless and a 16 Liter gas tankless.

All venting must be done in accordance with local codes and regulations. Local building codes from city to city and state to state will vary. Some jurisdictions may allow venting material not allowed by other jurisdictions.

All jurisdictions in North America allow for Z-Vent material to be used for venting tankless hot water heaters. The condensation of a tankless water heater is slightly more acidic than that of a standard water heater. Z-Vent is double walled stainless steel vent pipe made specifically for venting tankless heaters. Z-Vent is intended for lifetime use and will never corrode or rust.

Some jurisdictions in North America allow for B-Vent to be used. B-Vent is double walled galvanized vent pipe made for standard water heaters and stove vent pipe. B-Vent is not lifetime material and will eventually corrode after extended use. Before deciding what material to use, you MUST check your local building codes to see what is allowed in your jurisdiction. If you choose to use B-Vent, you MUST check it at least monthly for corrosion and replace vent pipes immediately if corrosion is detected.

Diameter of the vent pipe is 4” for 5L, 4” for 10L, and 5” for 16L units. Use the coupler provided with your unit for installation on the 5L and 10L units. Vent pipe attaches directly to the unit in 16L models.  For the 16L tankless when using the Z-Flex stainless steel venting you may also need a 5" stainless universal adapter and then a 5" single wall to double wall stainless adapter if you are going to use 5" double wall stainless steel venting.

For more information about the venting material you may need for your Marey tankless water heater, please consult the Marey Corporation or refer to the installation manual with the heater but the most important fact is to check what your local code requires!!

To order any of the Z-Vent single wall or double wall stainless steel venting pipe, adapters etc.  please call us at our toll free number 888-726-9752.

Hydronic Testing of Bosch Gas & Electric Tankless Water Heaters

All of the Bosch gas and electric tankless water heaters are tested from the factory before shipping.  The Bosch tankless water heaters are pressure tested for functionality, operation and leaks.  Bosch always ensures that the Bosch tankless water heaters are 100% reliable and operational when they leave manufacturing.

When Bosch has finished testing the gas & electric tankless heaters they will then place colored caps (red for electric tankless or yellow for the gas tankless) on the water inlet and outlet of the heater to prevent any residual water from damaging the insides of the unit and the box it is packed in.

Please see the image below that shows the caps on the bottom of a gas tankless water heater.

Humphrey Indoor Gas Light Accessories

Globaltowne carries a full list of accessories and replacement parts for the Humphrey Indoor Gas Lights. We have large quantities of the Humphrey Indoor Gas Light Accessories, including replacement globes, preformed mantles, tie-on mantles, burner noses, nozzles and much more.  Please see below for descriptions and a link to each part.

The Humphrey Half Frosted Pyrex Replacement Globe L6-20A is intended for use with all of our Model 9 and 9T Humphrey Indoor Gas Lights. The Humphrey Half Frosted Pyrex Replacement Globes are also sold in a pack of 6 Globes L6-20A-6PK (6 Globes).

Humphrey Preformed Mantle L13-2 for Humphrey Gas Light Model 9 (1 Mantle). The Humphrey Preformed Mantle L13-2 is intended for use with all Model 9 Humphrey Indoor Gas Lights.  Use only in stationary locations such as buildings (not recommended for recreational vehicles).  The L13-2 preformed mantle is intended for use with burner nose L12-2A.  Please note that Humphrey Indoor Gas Light part numbers that begin with 9T do not use preformed mantles.  The Humphrey Preformed Mantles are also sold in packs of 6 and are L13-2-6PK (6 Mantles).

The Humphrey Tie-On Mantle L13-6 and sold as L13-6-5PK (5 Mantles) is intended for use with all of our Model 9T Humphrey Indoor Gas Lights.  The L13-6 is intended for use with burner nose L12-11A.  Please note that Humphrey Indoor Gas Light part numbers that begin with 9 (not 9T) do not use tie-on mantles.  The Humphrey Tie-On Mantle also comes in a pack of 25 and is L13-6-25PK (25 mantles).

The Humphrey Clip-On Mantle L13-8 and sold as L13-8-5PK (5 mantles) is intended for use with all of our Model 9T Humphrey Indoor Gas Lights.  The L13-8 is intended for use with burner nose L12-11A.  Please note that Humphrey Indoor Gas Light part numbers that begin with 9 do not use clip-on mantles.  The Humphrey Clip-On Mantle also comes in a pack of 25 and is L13-8-25PK (25 mantles).

The Humphrey OPK Pendant Kit is used for mounting all Humphrey Indoor Gas Lights to the ceiling.  The pendant kit contains parts to mount 1, 2, or 3 gas lights.  Please note that all gas lights are sold separately.

The Humphrey High Altitude Nozzle for Humphrey Gas Lights L9-52A is for use on all Humphrey Propane Gas Lights above 4,500 feet.

The Humphrey Replacement Burner Nose Seal L24-15-6PK (6 seals) is a gasket for use with either Burner Nose L12-2A or Burner Nose L12-11A.  Please note that the replacement seal (L24-15) must be replaced anytime the burner nose is removed after the lamp has been used.

The Humphrey Bunsen L10-71A is the part between the nozzle and the burner nose.  This part will work with both the Humphrey 9 and 9T series of Gas Lights.

Humphrey Indoor Gas Lights

Globaltowne now has all of the Humphrey Gas Lights in stock.  We have large quantities of these Humphrey Indoor Gas Lights available in a variety of colors, including Rustic Walnut, Hunter Green, Pebble Gray and Natural Almond.  We have both preformed mantle lights as well as tie-on mantle gas lights.

Below is a full list, model number and color of all the Humphrey Gas Lights:

Humphrey Gas Lights (Preformed Mantle)

                  Humphrey Indoor Gas Light - Polished Brass (9HPB) 

                  Humphrey Indoor Gas Light - Classic Chrome (9CC)

                  Humphrey Indoor Gas Light - Pebble Gray (9PG) 

                  Humphrey Indoor Gas Light - Hunter Green (9GR)   

                  Humphrey Indoor Gas Light - Natural Almond (9NA)     

                  Humphrey Indoor Gas Light - Rustic Walnut (9RW)   

Humphrey Gas Lights (Tie-On Mantle)

                  Humphrey Indoor Gas Light - Polished Brass (9THPB)

                  Humphrey Indoor Gas Light - Classic Chrome (9TCC)

                  Humphrey Indoor Gas Light - Pebble Gray (9TPG)

                  Humphrey Indoor Gas Light - Hunter Green (9TGR)

                  Humphrey Indoor Gas Light - Natural Almond (9TNA)

                  Humphrey Indoor Gas Light - Rustic Walnut (9TRW)

We also carry a large supply of Humphrey Gas Light Accessories, including preformed mantles, tie-on mantles and clip on mantles.  We also carry burner noses, seals, spare globes and pendant kits.

Humphrey Gaslights are currently manufactured by Midstate Lamp, but in the past they were manufactured by Humphrey Products and by Paulin Products.

Bosch Therm 330PN is the Direct Replacement for Bosch 1000P

The new Bosch Therm 330PN is the direct replacement for the retail model Bosch 1000P.  Bosch is no longer making the retail model heaters and is only selling wholesale versions.  The Bosch 330PN comes in either Natural Gas (NG) or Liquid Propane (LP).  The only difference between the 330PN and the retail model 1000P is the color of the front cover.  The 330PN has a silver cover as the older 1000P had a white cover.  All of the other specifications are the same.

Specifications for Bosch Therm 330PN:

• Piezo ignition system requires no electrical connection
• 78%+ thermal efficiency
• 75,000 BTU maximum input
• 3.3 gallons per minute capacity at 35F degree rise
• Endless hot water for 1 application at a time
• Minimum activation flow rate of 0.5 gallons per minute
• Minimum of 30 psi water pressure required
• High to low temperature control
• Vents with 4" galvanized B vent – natural draft
• Built for durability and serviceability with 15-year warranty and 20+ year life expectancy
• Available in NG and LP models

The Bosch 330PN is also a good replacement heater for the older Aquastar 38B as they both are similar in BTU size and both take a 4" vent pipe.

The Bosch 330 PN could also replace the older Paloma PH6.  The 330 PN is 75K BTU and the PH6 was 43,800 BTU but both heater are good for small applications for camps and cottages.  The 330PN takes a 4" vent pipe like the PH6 did.  Please be aware that the 330PN requires a minimum of 30 psi of water pressure.

Service Bulletins for Older Bosch Aquastar Gas Tankless Water Heaters

Bosch has a series of service bulletins for the older retail model Bosch Aquastar and also the compact models such as the 1600P & 1600H.  These service bulletins can be very helpful with installation questions and when having issues with the Bosch tankless water heater.

Service bulletins can help with fixing an issue or with servicing your Bosch tankless water heater.  Please keep in mind and be safe when working on a gas appliance.  You can also contact Bosch directly or have you service agent contact Bosch technical support at 800-642-3111.

Link to:
G3 Service Bulletins for GWH 2700 ES and GWH 2400 ES

CT Service Bulletins for GWH 1000 P, 1600 P, 1600 H

G2 Service Bulletins for GWH 2400 ES/ESO, 250SX/SXO

AquaStar 38B, 125 Series Gas Tankless

AquaStar VP Series Service Bulletins

 AquaStar 240FX Service Bulletins 

Installing Bosch Gas Tankless Water Heaters in Bathrooms & Bedrooms

It is very dangerous to install a Bosch gas tankless water heater or any other gas appliance in a bathroom or bedroom that draws it's combustion air from that room.  Any Bosch gas tankless water heater or gas appliance that is naturally drafting and draws it's combustion air to burn from the room it is installed would deplete the oxygen in the room and cause asphyxiation.  The only Bosch gas tankless water heaters that are approved for installation in a bathroom or bedroom would be the direct vent ones.  The direct vent units are a twin pipe system and exhaust their gas to the outside and also take their combustion (intake) air from the outside.  Any direct vent unit installed in a bedroom or bathroom MUST take the combustion air from the outside.

It is against National Fuel Gas Code (NFGC) section 10.28.1 to install a gas fired appliance in a bathroom or bedroom where the door is normally kept closed.  This refers to all gas appliances that take their combustion air directly from the room they are in.  The only time a naturally drafting gas appliance shall be installed in a bathroom or bedroom is if they are installed within a closet with a self closing weather-stripped door with no openings.  All combustion air shal be obtained from the outdoors in accordance with section 9.3.3 of the NFGC.

Please also consult your local codes and local inspector for a safe installation.  Remember it is your life!

Bosch AquaStar 125X Water Valve Assembly (Conversion Kit)

The Bosch AquaStar 125X Water Valve Assembly Conversion Kit Part number 8707002810 is the 

replacement Water Valve assembly for all Bosch AquaStar 125X tankless water heaters.

This part is also is the replacement Water Valve for Bosch AquaStar 125FX tankless water heaters starting 

with a serial number of 380 or lower.

Bosch Aquastar 250SX/250SXO Water Valve with Engine

The Bosch Aquastar model 250SX/250SXO water valve with engine part number 8708505018 (old part number 8708505016) is the replacement watervalve for all Bosch Aquastar model 250SX/250SXO tankless water heaters.

This is also the replacement water valve for the Bosch Aquastar 2400E tankless water heater.

Bosch AquaStar 2700ES / 2400ES Heat Exchanger

The Bosch AquaStar 2700ES / 2400ES Heat Exchanger Part 8705406422 is the replacement heat exchanger for all Bosch AquaStar 2700ES and 2400ES tankless water heaters.

This part is also the replacement Heat Exchanger for the Bosch Therm 940ES, 940ESO, 830ES and the Bosch Evolution 500.

Bosch AquaStar 2400E / 2400EO / 250SX / 250SXO Heat Exchanger

The Bosch AquaStar 2400E / 2400EO / 250SX / 250SXO Heat Exchanger Part 8705406285 is the replacement heat exchanger for all Bosch AquaStar 2400E, 2400EO, 250SX and 250SXO tankless water heaters.

This part is also the replacement Heat Exchanger for the Bosch ProTankless 635ES and 635ESO tankless water heaters.

Bosch Aquastar 125BS/1600PS Heat Exchanger

The Bosch Aquastar 125BS Solar Heat Exchanger Part number 8705406189 is the replacement heat exchanger for the Bosch Aquastar 125BS tankless water heater. It is also the replacement heat exchanger for the Bosch Aquastar 1600PS tankless water heater.

The Bosch Aquastar 125BS/1600PS Heat Exchanger will NOT work for the Bosch Aquastar 125 series, 425PN, 425HN and 425HNO tankless water heaters. Please click the link for a Bosch Aquastar 125 series heat exchanger part number 8705406380.

Bosch AquaStar 1600 Heat Exchanger

The Bosch Aquastar 1600 Heat Exchanger Part 8705406386 (87054063860, 8-705-406-386-0) is the replacement heat exchanger for all Bosch Aquastar 1600P and 1600H tankless water heaters. It is also the replacement heat exchanger for the Bosch Therm 520PN and 520HN tankless water heaters and for all Bosch ProTankless 425PN and for certain Bosch ProTankless 425HN (with serial numbers starting 686 and higher) tankless water heaters.

The Bosch Aquastar 1600 Heat Exchanger will NOT work for the Bosch Aquastar 125B, 125BO, 125BL, 125X, 125HX, 125FX and the following Bosch ProTankless water heaters: 425EF, 425HN (with serial numbers starting 685 and lower) and 425HNO. Please click the link for the Bosch AquaStar 125 series heat exchanger part number 8705406380 (87054063800, 8-705-406-380-0).

Please call us at 888-726-9752 with questions or to place your order.

Bosch Aquastar 125 & WR400 Series Heat Exchanger

The Bosch Aquastar 125 Series Heat Exchanger Part #8705406380 (old part number 8705406235) is the replacement heat exchanger for all Bosch Aquastar 125 series and WR400 series Bosch tankless water heaters (regardless of Serial Number).  Astravan is a company in Canada that use to distribute the older Bosch WR400 series tankless water heaters.

Heat Exchanger Part #8705406380 (87054063800, 8-705-406-380-0) is the direct replacement for the following Bosch tankless water heaters:

125B, 125BO, 125BL, 125X, 125HX, 125FX and the following Bosch ProTankless water heaters: 425EF, 425HN (with serial numbers starting 685 and lower) and 425HNO, WR400-1KV1P23S3100, W400KD5  P23S3100T2, WR400-3K V1B23S3100, WR400-7K  V1G23S3195, WR430-3K  VM1E23S3190, WR430-3K  VM1E23S3195

The Bosch Heat Exchanger Part #8705406380 is NOT compatible with the following models:

125BS, 1600P, 1600H, 425PN, certain Bosch ProTankless 425HN (with serial numbers starting 686 and higher), 520PN, 520HN, WRS400K 1P23S3100T2.

Please call us at 888.726.9752 with questions or to place your order.

Ariston Anode Rod and Ariston GLKIT

Spare parts are available for he Ariston electric mini-tank water heaters. These spare parts are user-replaceable.

For the Ariston Gl2.5 and the Ariston GL4 mini-tank water heaters you can replace just the sacrificial GL Anode Rod (#574305) or you can get the Ariston GLKIT for the GL2.5 and Gl4 models. This GL KIT includes the GL Anode Rod (#574305) as well as the GL heating element (#994103) and the GL gasket (#994147).

The GL Anode Rod and the GL KIT will also work for the Ariston GL2.5Ti and GL4Ti mini-tank electric water heaters as well as the now-obsolete Ariston models P10S and P15S.

Similarly, for the Ariston GL6+ mini-tank water heater you can replace just the sacrificial GL6+ Anode Rod (#570241) or you can get the Ariston GL6+KIT for the GL6+ model.

Replacing an Aquastar 125BL Low Pressure Unit with a Bosch 345ESR/450ESR

The older Bosch Aquastar model 125B LP L (Liquid Propane) or 125B NG L (Natural Gas) was 117,000 BTU and was a naturally drafting unit that was good for one major application at a time. The Aquastar 125BL unit was a low pressure unit design for non modulating applications for heating systems in conjunction with domestic hot water.  The Bosch 125BL had a standing pilot light and took it's combustion air from the room it was installed in.  The 125BL had to be vented with a 5" B-vent double wall venting going a minimum of 6' up through the roof vertical to a raincap.  The 125BL unit could have been vented out the sidewall also with the AQ1 powervent kit (now discontinued). The Bosch Aquastar 125BL unit is discontinued now and has not been made for over 8 years or so. The replacement model for the older Bosch Aquastar 125BL would be the Bosch 345ESR or 450ESR recirculating units.

Bosch 345ESR/450ESR

The gas tankless recirculating heaters, Bosch 345 ESR and the Bosch 450 ESR are temperature modulated and have electronic ignition. The ESR stands for Electronic ignition, Sealed combustion and Recirculating. These recirculating heaters are designed and approved for heating and recirculating potable water in conjunction with an indirect storage tank.  The Bosch 345ESR and the Bosch 450ESR would be able to replace the older Aquastar 125BL unit but there would have to be significant changes such as the venting is stainless steel, combustion air taken from outside using 3" PVC and that the gas line sizing would have to be appropriate.

The 345/450 ESR are not approved or designed for closed loop heating applications. The ESR units are not a tankless heater as they have no flow switch to respond to flow. Instead it’s a recirculating water heater designed for tank loading applications such as the older Aquastar 125BL units were designed for. When an AquaStat (not included) hooked up to a tank tells the ESR that water needs to be brought back up to temperature, the ESR will tell a circulator (not included) to turn on to create flow through the heater to reheat the water in the tank. Please refer to the installation and applications manual.  The basic setup for the indirect tank, aquastat, recirculation pump, check valves, etc. should be basically the same for the new ESR heaters.

The Bosch 345 ESR recirculating heater is a 95K BTU unit and can deliver 3.5 GPM at a 45 degree rise. Efficiency is 82%


The Bosch 450 ESR recirculating heater is a 120K BTU unit and can deliver 4.5 GPM at a 45 degree rise. Efficiency is 81%

The temperature control range for both heaters can be set anywhere from 115°F (45°C) - 190°F (90°C)

The 345/450 ESR comes with a standard ¾” pressure relief valve.

The 345/450 ESR has a special built-in freeze prevention cycle and is controlled by a sensor. Freeze protection is always assured by the operation of the appliance. If the primary NTC (temperature) sensor detects temperatures 9°F below the selected temperature, the appliance starts on minimum power until the sensor reads selected temperature. In the case of minimum set point temperature then it will start at 41°F. The use of non-potable additives like glycol is not approved.

The Bosch 345 ESR and the Bosch 450ESR must be installed indoors according to the provided installation manual. The 345/450 ESR is NOT approved for outdoor installations.

The Bosch 345/450 ESR recirculating heaters must be vented in accordance with the installation manual and require Category III 3” stainless steel sealed venting for the exhaust. These heaters are direct vent units and must be vented directly to the outside in accordance with the installation manual. These heaters cannot be combination vented with any other appliance. The intake should be taken from the outside and 3”PVC or other material can be used only for the intake air.

The Bosch 345/450 ESR recirculating heaters are gas specific so they cannot be converted from one gas type to another.

GlobalTowne.com Launches a Brand New Web Site

Global Pro Tankless Supply is pleased to announce that on May 6, 2013 we launched a brand new GlobalTowne.com web site.

This new web site is built on the Magento platform and is loaded with new and exciting features. In addition to providing our customers with a more secure online store we are now able to support PayPal and Google Checkout payment options in addition to accepting Visa, Mastercard, American Express and Discover.

We have retired our original osCommerce online store that had served us well since we first began selling online in 2004.

We are still in the process of adding all of our parts to our new online store. If you are looking for Bosch gas, propane or electric tankless water heaters, Bosch PowerStar electric mini-tanks, Bosch tankless replacement parts, Z-Flex Z-Vent stainless steel venting, Humphrey indoor gas lights and accessories, WebStone and Cimberio isolation valve kits, Flow-Aide descaling kits and solution, Sentinel Hydrosolutions leak defense systems or Virgo whole-house water filtration and conditioning systems and you cannot find the part you are looking for, please call us at 888.726.972 for assistance.

While our look and feel has changed, our operation has not; we are still open 24/7 and ship out of our four US-based warehouses. Most importantly, our commitment to providing superior customer service remains.

Replacing an older 125FX LP with a Bosch 660EF LP

The older Bosch Aquastar model 125FX LP (Liquid Propane) was 117,000 BTU and was a direct vent unit that was good for one major application at a time.  The 125FX LP had electronic ignition and was fan assisted and took it's combustion air from the room it was installed in.  The heater had a built in fan so the heater could be vented right out the sidewall of the building.  The 125FX LP had to be vented with a 4" sealed stainless steel venting going a maximum of 15' out the sidewall of the building into the FXHood.  The FX Hood was a termination hood specifically designed for the 125FX LP and had a built in flapper to keep cold air from penetrating the vent pipe and freezing the heater.  The Bosch Aquastar 125FX LP is discontinued now and has not been made for over 8 years or so.  The replacement model for the older 125FX LP would be the Bosch 660EF LP.

Bosch 660EF LP



The Bosch 660EF LP can be used for a direct replacement for the older Bosch Aquastar 125FX LP.  The 660EF Lp is also a direct vent unit, it is 140,000 BTU and has electronic ignition and is fan assisted to vent right out the sidewall of the building.  The 660EF LP has 3/4" water and gas connections on the bottom of the heater.  The 660EF LP also takes it's combustion air from the area where it is installed.  The 660EF LP is designed for 3" stainless steel venting and has a special 660EF adapter required for the top of the unit to attach the venting to.  You would then need to use a 3" to 4" increaser so you could go to 4" stainless steel venting and can then be adapted to hook up right to the existing FXHood.

If the older Bosch Aquastar 125FX LP was originally installed with 4" galvanized venting and there was no FX hood in place then the installer could use the AQ5EF sidewall vent for the new Bosch 660EF LP.  The AQ5EF sidewall vent kit comes with the 660EF adapter, 3"x90 degree elbow, 3oz tube of high temp sealant, wall thimble, termination box, a 3"x12" piece of stainless pipe and a 3"x18" piece of stainless pipe.



Z-Flex 3" & 4" Silicon Seals for Stainless Steel Venting

Z-Flex Inc. is a major manufacturer of category 3 stainless steel venting material (AL29-4C).  All of the stainless steel venting is a sealed vent pipe.  The stainless steel vent pipe has a seal on one end inside the female end of the pipe.  The vent pipe has a built in clamp on the female end also. 

The seal on the inside of the 3" & 4" stainless venting keeps the vent pieces sealed when connecting them together.  If there is ever a need to take the venting pieces apart then the gaskets would have to be replaced as they would be damaged by the prior heat and condensation.

Globaltowne has extra 3" & 4" replacement silicon seals in stock in case the venting has to be taken apart.  These seals are required for all the stainless venting and prevent any gasses from getting out into the home.

New Ariston GL6+S Electric Mini-Tank Water Heaters

The new Ariston GL6+S electric mini-tank water heaters have just arrived. This water heater is the direct replacement for the recently obsoleted Ariston GL6+ (GL6PLUS).

The main difference between the older GL6+ and the new GL6+S is that the GL6+ came with a power cord that plugged directly into a 120V wall socket while the new GL6+S does not come with a power cord. The GL6+S must be hardwired at the time of installation.

Globaltowne does carry a 6' cord for the Ariston GL6+S

Here are the features of the new GL6+S:

• 6-year warranty on tank
• Glass-lined tank for longer life
• Mounts on wall or floor
• Temperature/pressure relief valve included
• Must be hard-wired to 120V
• Dimensions: 17.5" x 17.5" x 14 1/2"
• Recovery at 90 Deg F Rise: 7 GPH
• 12.5 AMPS and 1500W Heating Capacity
• Temperature Range: 65 Deg F to 145 Deg F
• Meets ASHRAE 90.1 Standard
• Relief Valve = Installed
• Power cord not included

The new Ariston GL6+S model has many new improvements since it has been upgraded. The mini tank has a new temperature adjustment knob on the front of the unit to raise and lower the temperature from 65 Deg F to 145 Deg F. On the older model you would have to remove the blue oval cover to access the temperature knob.

The Ariston GL6+S model has a new improved thermostat that features a new sensing probe that is attached to the thermostat and inserts into the cavity of the new element so the heater can adjust temperatures quicker and maintain a more consistent heat.

Steve