Robertshaw Gas Valve Removal - Help its stuck!

[Martylock]

I have got a Robertshaw gas valve which feeds into my tray burner on a Comfortzone heater. The heater does not turn on automatically which I am presuming to be down to a possible faulty valve as I have explored what I believe to be all other avenues (the heater will start and stay on by jumping across black and blue terminals).

The inlet pipe, pilot and millivolt connections are easy enough to remove, but I can't remove the valve from the outlet pipe to fit the new one. Is there a technique or something obvious holding it on?

 

[Bama Rambler]

The valve just unscrews from the black pipe once every thing else is disconnected. However, if the unit will light and stay lit by jumping the black and blue wires the valve appears to be good. The relay (red box) or signal that energizes the relay (small wires on bottom) is most likely the problem.

 

[Martylock]

Many thanks. I took the unit off and the sheaths around wires at the burner end are a bit frayed. (see pic) could this be the problem? What is it called if I need to buy a new one?
How would I replace the red box if that is suspect?
I have a brand new valve which I wanted to try as it has a relay on it, but I still cannot unscrew ythe old one off the black pipe. I have put the valve in a soft jawed vice and am trying to move the black pipe but it does not want to budge and I am fearful of applying too much pressure. Do I need a joint sealant remover/dissolver?
To make things more interesting, once re-assembled, it still won't auto light with the pilot on and when I jump the black and the blue the pilot now goes out :-(
Big pool party in 10 days time!
Very grateful for some more top tips...

 

[Bama Rambler]

If that's bare wire I'm seeing there, that's definiely one problem.

I'm not sure you can change the relay on the valve. Your picture doesn't give a clear enough view of how it's mounted to the valve.

 

[Melt In The Sun]

Agreed; that's definitely a problem and likely the problem. Start with the obvious stuff!

 

[Martylock]

Excellent. Do you know what the part is called? ie the red and brown copper wires in the sheath that runs to the igniter from the valve? I need to know so I can order/buy a new one.

 

[Melt In The Sun]

No idea what it's called. If you have the manual, there may be a parts blowup that shows it, or you could call the manufacturer.

That said, I would probably remove the whole cord, try and disassemble the rubber-coated plug, remove the old wire, and re-solder new wire to the plug and the contacts at the other end. The plug may not be salvageable, but I'd at least give it a shot.

 

[Bama Rambler]

That's the thermocouple (actually thermopile). You should be able to get one where ever you got the valve. It senses the pillot flame to keep the valve open.

There's also a wiring diagram just to the upper right of the first picture you posted.