Single-stage vs. stepped gas valve on Burnham P206 hydronic boiler ?

GaryF

Long story made very short: After a series of problems with maintaining a standing pilot, my HVAC repair contractor replaced the gas valve on my circa-1987 Burnham P206W hydronic boiler in March 2018. The original valve on the boiler was a 2-stage "stepped opening" valve (Essex model SX242NRT to be exact). After installing a series of Honeywell VR8300 A 4508 valves that all failed to hold a pilot (apparent manufacture defect with this batch of valves), he finally ended up completing the gas valve swap with a White-Rogers Model 36C03 Type 300, which is a conventional single-stage valve. When I gently challenged him on the replacement being single-stage vs. a stepped-open valve, he said they do this kind of swap "all the time" with no problems. With Spring weather on the way and the heating season nearly over, I let it go. Later, I contacted the Burnham factory resource, and they said they do not respond to homeowner questions and redirected me back to my repair contractor. With my repair contractor's position already clear, I am tee'ing up the question here for input...

The replacement single-stage 36C03 valve seems to be operating just fine. Do I need to consider paying for and getting this valve swapped out for a 2-stage valve in the long term ? Some documentation I have seen seems to imply the use of a stepped valve is mainly to limit burner noise. In my case, burner noise when firing the furnace with the single stage valve does not seem at all excessive.

This is a not-inexpensive proposition, likely $180 or more for just the new valve. Labor on top of that unless DIY (which I would prefer not to do on the gas side piping -- as a homeowner I replace thermocouples and do work on the water circulating side but prefer to leave the gas piping repairs and pressure adjustments to a pro).

Comments and input please. Thanks in advance !!

ChrisJ

@Tim McElwain

John Mills_5

They are both single stage. The step opener doesn't open as fast as the 36C03. On some larger appliances, opening fast can be noisy or rough ignition. If you are not having any issues, could be OK. Timmy might advise otherwise for liability reasons, not putting on the OEM part.

Tim McElwain

It is incorrect to replace a "step opening" (it is not two stage by the way) valve with a standard opening valve. The boiler was tested and approved with step opening so that should be continued. It will definitely affect the light off other wise. The step opening usually opens on low fire and then ten seconds later goes to full fire. This is to insure safe lighting.

What was wrong with the Honeywell VR8300A - 4508 is that it is a standard opening valve not a "step opening" valve which is probably why you had problems. It should have been a VR8300(C) which is Honeywells step opening valve.

I am going to look up the original Essex SX242 NRT to see if it is a step opening valve?

JohnNY

In a field-service truck, stocking slow-opening gas valves as opposed to universal standing-pilot gas valves is a difficult and expensive thing to do. I try to get OEM whenever possible but there's more than one way to make a very simple atmospheric appliance like the one you've got work well and safely. My quick advice to you is to not worry about it. Your boiler is about to turn 32 yeas old. When the time comes (soon, mind you), you'll get a nice new boiler with all modern functionality and updated safety controls.

Tim McElwain

Essex valve is Step Opening https://www.radwell.com/en-US/Buy/ESSEX/ESSEX/SX242NRT and is still available from Radwell.

Tim McElwain

John there is a difference between a slow opening valve and a step opening valve.

JohnNY

Tim McElwain said:

John there is a difference between a slow opening valve and a step opening valve.

Of course. You're right. Happy New Year, Tim.

GaryF

Thanks all for your comments and input. Now I need to consider all this and decide how to proceed. Maybe just buy that surplus Essex valve and install myself...