Descaling My Bosch C1050ES Tankless Water Heater

A few weeks ago I descaled my Bosch Greentherm C1050ES-LP Condensing Tankless Water Heater and it was far easier than I had imagined it would be. The total elapsed time to do the complete job was less than an hour. I took a few pictures as I went through the steps.

The above picture shows the JC Whitlam Flow-Aide Descaler Kit. This kit contains the (2) 5' hoses, the submersible pump, the pump intake filter and one quart of Flow-Aide descaling solution.

The above picture shows my Bosch Therm C1050ES-LP condensing tankless water heater and my Webstone 44443WPR Lead-Free Isolation Valves. I took this photo after I had closed the two yellow-handled main water valves and after I had opened the two service ports. I had to place a bucket beneath the two valves to catch the water that was in the internal piping of the tankless water heater.

The above picture shows the two 5' hoses that come with the Descaling Kit attached to the two service ports on my Webstone Isolation Valves.

The above picture shows the Flow-Aide bucket and descaling solution. I had already put one gallon of cold water in the bucket and mixed in the one quart container of Flow-Aide solution. This descaling solution is non-toxic and bio-degradable.

The above picture shows the submersible pump output attached to the cold water connection on my tankless water heater. The pump is not plugged in yet.

The above picture shows the included intake filter attached to the submersible pump input. This filter prevents any debris from being run through the tankless water heater. The pump is still not plugged in.

The above picture shows the descaling process in action. Here you can see the hose from the hot water connection to my water heater just hanging into the bucket. You can also see that I have plugged the submersible pump into a GFCI protected 110 V power outlet.

I let the descaling process run for about 30 minutes. I then emptied out the bucket and rinsed it out thoroughly. I then put about a gallon of cold water into the bucket and I ran that cold water through my tankless water heater for about 5 minutes just to clean it all out.

Lastly, I disconnected everything and then I closed the two service ports on my Isolation Valves. I then opened up the two yellow handles to let the water flow back into my water heater. When I turned on a hot water demand everything worked perfectly!