Hoffman Mixing Valve

Wayco Wayne_2

I'm looking for information on a Hoffman Mixing valve WMMV. I have a bunch of them on some Weil mclean Gold boilers and need some specs on them to give my technicians. Also where do we get the cartiriges if we need to replace them?

Wayco Wayne_2

Got answer

 Called Weils Mcein, and found out the mixing valve and replacement parts for it are no longer available. Time to get a little creative. No problem.

hot_rod

maybe just a cleaning?

there is not much to fail inside a thermostatic valve, just a small thermal cartridge. Most time they just seize from bad water conditions and a good cleaning will get them mixing again.



If the thermal "pill" is bad, maybe that part is still available?



Try Able Distributing in Chicago they have a lot old old Weil parts.



hr

Jean-David Beyer

Cleaning mixing valves.

I have a fancy two-stage mixing valve for my darkroom. It has a big knob with which to set the desired temperature, and a big 3-inch thermometer that tells me what temperature I am getting. It is open-loop; i.e., fresh hot and cold water go in, and after the mixed water is used, it goes down the drain. So I probably get maximum deposits. The two stages are a pressure-balancing valve so that hot and cold water to the second stage are at the same pressure, even if someone flushes. I rebuild it every 10 years or so. Valves like that are too expensive for me to put in my shower, but if you are rich, you might like one. If you draw at least 1/2 gallon per minute or at most 3 1/2 gallons per minute, it will hold +|- 1/2 degree F.



There are two reasons I have had to rebuild. 1.) there are a lot of O-rings that deteriorate due to the crud in the water, and 2.) calcium deposits cause problems. A weak acetic acid bath and an old tooth brush can get rid of a lot of that. Oh! there is also a Teflon valve seat in there. so 3.) that valve seat needs replacement too. I have never had the thermo capsule fail with this valve (now 25 years old).



I used to have an English-made valve that needed rebuilding almost every year. It did get deposits, but where my American valve has most of the moving parts made from precisely machined stainless steel, the English ones were made of a rubber like compound. And the rubber things would swell up from whatever is in my water and the valve would stop regulating.



But these valves are really very simple. I am not a plumber, but I can rebuild a two-stage valve in a few hours. If I were a professional, I suppose I might do it a bit faster, but with the meter running, maybe buying a new valve would be a better use of the money.