Robert Shaw gas valve.

A little over a week ago, maybe two weeks
ago I posted a question about the Robert
Shaw brand gas valve in a heater I have.
Thanks for the suggestions.

The old valve would not respond to the
thermocouple. The old valve used a
capillary tube type thermostat but I
decided to get a new valve that requires a
wall thermostat. I looked at the dizzying
array of valves on the Robert Shaw website
and came up with the perfect fit, 100,000
btu 1/2" inlet and outlet, snap valve, just
what I wanted. When I tied to purchase this
valve on a retail website I found this
valve was recalled. Bummer! Back to the
blackboard. I finally came up with this
valve, 100,000 btu same configuration but
soft start which can be converted to snap
start if needed. What I don't know is what
the two wires coming out of the red
thermocouple hole area are for. This heater
uses a pilot light.

Depending how it is set up those wires would be for a high temp saftey. Like in a fryer. 425? shut off.

Thanks. So I can ignore the wires. I assume a high limit switch would complete a circuit between the two wires to shut the gas down.

Hold on,,,, I went and looked at some of the Robert Shaw controls in our shop. What you bought is not like anything we have. First off that black knob with high low on it is adjusting the pressure diaphram that really should be set with a folded manometer to a certian water columb pressure. It makes it so the valve will allow a certian amount of gas in. Hi/lo flame. The two wires would need to be hooked together. Your thermal couple would supply the tiny amount of power to keep the valve open. Make and break ,on off, heat no heat deal, thermostat would hook to the black block. These valves are usually set up for milli volt and some are even micro volt. They also come in 24 volt AC supply and there are 120volt types. This is the trouble with fixing "home" appliances, and commercial equipment. Some of the ovens we have in the kitchens have 1 1/4" gas lines going to them. NOW. NOW!!!! Looking at your photo very carefully....that red cover, if you look inside of it there should be a threaded hole. That is where your thermal couple should screw in. At the bottom of that hole is a blue plastic block with some squished wire. Those two wires would go to a hi limit, and your thermostat would hook to the screws on the black block. Hope this is makeing sence. The valve in the first photo is for a Pitco fryer. Very common valve in our industry. Ours doesn't have that red cap but that is where the thermal couple screws in. For goodness sakes don't cross thread it! Also it is only a few foot inches of tightness. To me this is so simple but trying to explain it on a forum! Ufda. Let me put up the photos and if you have problems get back to me.

(quoted from post at 17:37:43 10/21/17) Thanks. So I can ignore the wires. I assume a high limit switch would complete a circuit between the two wires to shut the gas down.

Click to expand...

Almost certainly, just the opposite.

More than likely it's intended for use with a normally closed limit switch that opens the circuit upon overheat.

Likely, you will have to jumper the wires together to get the pilot control to "latch".

That being said, BE CAREFUL!

The tag states 24v. When I scrolled through the Robertshaw site I watched carefully to make sure I had a 24v control instead of milliamp. I will just have to play with the wires to see if they need to be jumpered or not. First I need to get a transformer, thermostat and some wire to get that part of it set up. Thanks so much for sharing your knowledge.

Oh, the flame adjustment knob, the old valve got to overfueling anyway. Last winter the flame was higher than it should have been, was yellow and soot was building up. Now I can fine tune as needed. This heater has a wide window in the front making the flame visible. If I was home I would take a picture.