Robert Shaw 7000 Series Gas Valve

[Paul of Dayton]

Hi Folks -

I lurked here a few years ago when my Trane Vapor Steam system was getting a new WM boiler. I learned much and have sweet, even heat... well, until now.

When I started the system this fall, the pilot wouldn't stay lit. Using the old water heater rule, I replaced the milivolt thermopile with a new exact replacement. Since then there have been 2 or 3 times I've had to relight the system. Tonight it won't relight. I put my digital voltmeter on the pile, after a minute or so it is at 750mv which is spec. I'm thinking the magnetic safety is shot. Any opinions? I plan to visit the local supply house for one tomorrow but I'd like to hear what the pros say. Thanks!

PoD

[gofish]

everything built by man will fail at some point in time.

[Bubba]

Its your thermostat. Its almost always the thermostat. Ask my customers. Make sure you use a good quality (expensive) digital programmable one. Change the low voltage wiring while you're at it. The wiring has to match the thermostat. Bubba

[Bob Pietrangelo]

How old is this WM boiler that it is still using a T-pile. I haven't seen a WM boiler with a T-pile in a very long time, I mean one that was built in a very long time, unless you had a used boiler installed a couple of years ago.

[Paul of Dayton]

New unit, fresh from the wholesaler, EHG95S, installed 10/02. It is a steam system. I have tried to find the magnet safety part today, there was a recall for newer valves of the same type and the magnet was all that was replaced. Nobody can get it. I called Robert Shaw and they can't get it. They think it's a special model for W-M. I may just replace the whole ding-dong valve. It shouldn't be too hard to find a slow opening valve with

1" fittings that will fit the 400,000 BTU burner... (but what a pain).

The first boiler I ever worked on had a manual lever on the side of the valve to use in power failures. It had one thermo-pilot and about 6 igniter pilots that were piped directly to the gas line. (I am not ready to trade the safety features of this setup, tho.)

There was supposed to be an electronic ignition option for this unit but the boiler guy recommended against it. So much for reliability of the old design.

Thanks!

PoD