Hvac

[Drm50]

This morning someone needed an electrician, that’s me. I need a HVac expert. My Furnance crapped out Sat morning. I know how to check and trouble shoot, it’s electrical. Ok, found my gas valve is bad. When I got Furnance I had to use LP. A couple years later got NG so put in conversion kit, new valve. That is valve I got to replace and there is no label on it. Is there a reference to find what valve I need by make & model? This is a Tempstar I put in early 90s.

[Jniedbalski]

Look at the build tag as make model serial number and call to ur local Ac supply house.you can also look on line to see if you can find it

[Jniedbalski]

What’s it doing or nothing at all? Does it start to light or no thing at all. Is it a high efenciey furnace with pvc flue pipe?

[dragon813gt]

The valves are pretty much interchangeable. Some are two wire while some are three wire(for pilot). I carried one Honeywell to replace them all. Came w/ bushings for 1/2” piping and wire harness if the control was two wire. Also had the LP conversion spring. Since it’s a Tempstar from the 90s there is no way it’s a two stage valve which a different can of worms.

[wv109323]

You should be able to take make and model and get a part number of valve as original. From that you should be able to find the equivelent in NG or LP as needed. Beware that many old part numbers are obsolete and make sure the updated unit is compatible.

[Drm50]

It is a two stage valve, getting 25v and drawing .1 amp when solenoid activates. I’ve been in circles on line with model number and haven’t found any chart to give me model replacement. Valve looks like White Rodgers. I want a valve to just hook up gas and plug in wires, don’t want to be messing around with valve guts.

[dragon813gt]

It is a two stage valve, getting 25v and drawing .1 amp when solenoid activates. I’ve been in circles on line with model number and haven’t found any chart to give me model replacement. Valve looks like White Rodgers. I want a valve to just hook up gas and plug in wires, don’t want to be messing around with valve guts.

You’re positive it’s two stage? They really didn’t exist in the early nineties especially w/ a budget brand like Tempstar. What are the terminals labeled on the valve and how many are there? Is it MV, MV/PV & PV? Regardless of valve you aren’t going to have to change any internals unless you’re converting to LP. A Honeywell VR8345M-4302 will work for all single stage applications regardless of ignition type.

[Drm50]

Tempstar was a premium brand at the time I bought it. It was a LP and run 2 seasons before I got NG. I bought conversion to NG, valve and burner orifices. Furnace is hot surface and that is only thing replaced in 30yrs. 3 wire to valve. NULK075DG05. I know HVAC guys have universal replacements for obsolete valves but unless I’m looking in wrong place I can’t find cross reference.

[Jniedbalski]

The ac / heating supply houses have all the old books that show the change over to new part numbers. I usually call them to get the new number and part. Some times u can get lucky and find a seller on eBay with the exact old part you need new old stock that sombody had sitting around for years and now want to sell. Got a few hard to find parts like this. The company’s quit selling some parts years ago and some times it’s the only way to find them.

[Jniedbalski]

Some times it’s only a relay on the board that goes out . Like say the gas valve relay. Or a fan relay.I have replaced a few and got them working when the parts store can’t get them. Also with the very small parts I usually take the bord to a tv electronics place in town. He use to fix and repair fighter jet electronics. He is really good and a lot better than me at soldering. Actually a lot lot better. My solder work will work but looked like a first grader did it.

[NyFirefighter357]

The valves are pretty much interchangeable. Some are two wire while some are three wire(for pilot). I carried one Honeywell to replace them all. Came w/ bushings for 1/2” piping and wire harness if the control was two wire. Also had the LP conversion spring. Since it’s a Tempstar from the 90s there is no way it’s a two stage valve which a different can of worms.

This ^^^^^^^^^^^^^^^

Cross reference the the gas valve itself not the Unit.

[JRLesan]

Don't count on some schlub behind the counter at the parts house selling you the proper replacement part; even if you take the old part in hand to show him. There's a reason he's selling parts and not out servicing. Ask me how I know...

[Wis Tom]

I've been in Hvac for over 30 years, but I don't give advice on anything gas. Blower, electrical, and inducer assemblies, no problem, but I don't have good enough insurance to give out internet advice on gas. Do you have a manifold gauge to test WC", if not, I have seen new values lately, not set at 3.5" WC, from the factory, for natural gas. Good luck saving money on an old Tempstar.

[.429&H110]

There are several "rollout"- sail -thermal link -thermostat -switches in a daisy chain powering the valve. They can open and still show volts, but not pass amps, like you see 0.1 amp. I would like to be sure it's the valve and not a poor connection before I screw pipe. Gas valves usually outlast appliances.