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mrraffer
12-21-2009, 03:25 PM
We just replaced a 23 year old Weil McClain boiler with a new Peerless WBV and immediately began having trouble with our domestic hot water supply, which was fine with the older boiler. I believe the problem may relate to a flow restrictor that is built into the new tankless coil. We have the tankless coil connected to a separate storage tank that filled with hot water from the coil by thermosiphon on the Weil McClain for 23 years. Now, with the same plumbing arrangement, the hot water doesn't flow into the tank. We have been forced to use the tankless without the tank, limiting the amount and pressure of hot water available.

My question concerns the built-in flow restrictor. Can it be easily removed or drilled out? I can find absolutely zip, nada, zilch about how this coil is constructed on the Web. My installer has not been any help in this regard. His suggestion was to spend another $1500 on an indirect tank. (Interesting, because he was the same installer who suggested adding the existing tank to the coil 23 years ago.) Up until a couple weeks ago, we had all the hot water we wanted with the system we had. As you might imagine, this is quite frustrating.

Is anyone familiar with Peerless tankless coils with built-in flow restrictors?

Thank you.

Peter Griffin
12-21-2009, 03:54 PM
First off you should have sprung for the indirect in the first place because not only will it give you all the hot water you will need, it will also cut your oil bill by 15% That said, the restrictor is there to limit the flow through the coil. Coils are rated in gallons per minute at x degree of rise depending on boiler temperature. Without the restrictor your water would run cold quite often.

On a separate note. Tankless coils do not meet plumbing code. They have never met plumbing code but most inspectors have overlooked that little item for years, believing that folks could not afford to do anything different. Do yourself a huge favor and get rid of the thing.