tankless hot water boiler - cold water


Old 05-27-00, 03:45 PM
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My 40 yr old Stewart Warnwer tankless hot water aint providing hot water anymore, The unit goes on when I turn on the heat. Are there parts or a cleaning kit I can use to recify the problem? If so are instructuions provided? I do have a lot of scaling buildup around the plumbing to the boiler.
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Old 05-28-00, 07:38 AM
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Based soley on what you posted, which I am not really clear on, I would venture a guess and say the flow valve is defective.

This valve senses the flow of water and volumn of water thru the unit and it fires up the burners.

If it's defective and doesn't sense any water flow, the burners do not fire up.

If it incorrectly senses the volumn of water flow or is restricted, you'll get cold or only warm water.

Good Luck,
Natural Gas Energy Consultant and Technician
Old 05-28-00, 09:07 PM
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Depending on actually how that thing is built, the age may give a clue, some of those flow valves had a thermostat in them sort looks like in a car application.

If that is the case the top of the valve screws off and you can just pop out the thermostat.

It was designed to give priority to hot water and squeezed down on hot water flow going to the radiators. It will work without it, and you get hot water again.

Just turn down the thermostat so the house doesn't call for heat when taking a shower, if you can't find a replacement.

Over the years the designs of those systems and how they were actually built and what the parts looked like changed but the design ideas are the same.

[This message has been edited by Rambler (edited May 28, 2000).]

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