Honeywell 3/4" valve replacement

Megawboiler

Greetings from western Canada. I am running a 100 yo+ converted coal fired boiler supplied through 3/4"Honeywell V88C2DJ5X2 with a Tekmar control panel. Single pipe, low pressure, 9 small to medium radiators. Fabulous system methodically balanced and maintained, love it. It seems the ancient Honeywell valve is crapping out as it clicks when the control goes into heat cycle but only opens about 10%. The picture above is the valve. It has a manual override right on the top of the valve so that is how I am running it now. I want to replace the valve and have looked at a Honeywell V800A1591. It has the standing pilot and same pressure rating. Neither Honeywell, Residio or local/regional suppliers have been able to help with a replacement recommendation...like nothing.
Any advice? I have all your books and have entertained my friends and some newbie HVAC people with boiler tours of what is the only steam heat system in this whole area.

Erin Holohan Haskell

Welcome, @Megawboiler. You can post pictures by clicking on the image icon in the toolbar. Here are more tips for using the forum: https://heatinghelp.com/forum-user-manual

mattmia2

Post some more pictures of the gas train from further back. Most likely you will have to replace it with a modern combination valve that contains the valve, regulator, and pilot safety and regulator. You will need a tech that is good with combustion analysis to set it up.

Megawboiler

Ok thanks. I have a good commercial gas fitter but just helping research parts possibilities. Photos of all components here now. Regulator is Maxitrol RV50. One pilot line is on the Honeywell valve and one is before the regulator. Is the one built into the shutoff above the filter the safety? Thanks in advance. Love the idea of replacing everything. Tekmar beta site as their factory is just down the road Current panel is their 279.

Megawboiler

mattmia2

The line before the main gas cock is the supply for the pilot burner. Where does the small tubing off 24v valve go? If it just goes in to the combustion chamber it is probably just to burn off the gas that leaks out if the diaphragm in the valve were to rupture. Is there a Baso switch connected to a thermocouple or something similar off to the right as to prove flame on the pilot before opening the main valve?

This is a pre total shutoff system, the pilot is always on. With a modern valve there is a valve that shuts off the pilot if the pilot is not lit. A picture to the right and maybe further back will tell us the rest of the story.

Megawboiler

Sooooo appreciating this brother and right you are. The pilot line from the 24v valve is the little orifice behind the thermocoupled main pilot. The main pilot is fed from that shutoff above the filter. There is a main shutoff further up also. Pics of everything here including burner at flame level it generates BEFORE I manually trigger the over ride on top of the valve.

mattmia2

You might check the voltage at that valve before you condemn it, it might be a bad contact in one of the controls that is causing too little current to reliably open the valve.

Megawboiler

Yes thanks. Working on checking all the wiring.

Megawboiler

Anybody have an idea how old this valve is. Honeywell claims no records of that part number.

mattmia2

Since it says Minneapolis-Honeywell and it isn't a total shutoff system, probably 50's or earlier.

Megawboiler

Wow, older than me!

Megawboiler

Hmmmm it still has the original low water shutoff / rust separator apparatus. Haven't tested that lately but it is entirely possible that those contacts are corroded or otherwise schmegma'd. I'll keep you posted.

mattmia2

i'd suspect a control that actually operates regularly like a pressuretrol first but it is very likely the valve itself is bad and not a terrible idea to replace all of it anyhow

retiredguy

Geeze, that gas valve set-up is not old or is just me. What you have there is an unvented "Maxitrol" gas pressure regulator with an orfice vent (not legal any more)), a standard but old diaphragm gas valve with a vent line to vent off the top of the diaphragm that goes to the pilot to burn off the vented gas (not legal any more), when the gas valve opens. On this type valve, the gas pressure does the opening and closing,(with the help of an internal spring), of the gas valve by routing the gas to the upper and lower chambers to raise or lower the diaphragm. You said that the valve only opens part of the way. My guess would be that the diaphragm is leaking (broken or split) and not allowing the top of the diaphragm to vent fully. See the white flame in the picture of the blue flame when the burner is lit. That is or could be the gas that is coming from the top of the gas valve diaphragm. Also, there is a standing pilot. You can replace what you have with an on/off gas valve or go all the way to a relite system.

By the way, this was "state of the art" when I got into the business after the Navy and tech school in 1968

Megawboiler

NH Owner thanks but spent much time going back and forth between Honeywell, Resideo and my local and regional suppliers. They all were provided with pics and specs. Nada. If you have provided them with that part number and got a different response please share. See new post.

Megawboiler

Update and news flash as I know you're all squirming with anticipation. You're right, its old. Check out the pic of the rust separator/low water switch.

Megawboiler

Now the good stuff . Thanks Mattmia2 voltage and current checked. See pics. Bypassed old low water switch and wired direct from transformer with Tekmar panel control. 25V and .4 amps at switch when panel calls for heat. Switch clicks but doesn't get more than about 10% to burner. Works just fine on manual override. Footnote, disconnected low water switch has continuity across terminals.

mattmia2

If @retiredguy thinks the diaphragm is ruptured it probably is.

There are people here who know the part number for a honeywell 24v standing pilot combination valve, just no one has answered with that yet.

Megawboiler

Gentleman start your answers! Hard to make out in pic but old cfh ratings for burner are 270/200.
Do people still put in filters like the one in the pic?
No cross reference numbers available but can someone recommend replacement parts for the whole apparatus from shut off valve forward?
Do I really need that second pilot line directly from the current valve?
Specs: standing pilot, 8oz, 24V, .39 amp, 3/4 inch
Thanks in advance. What a team!

retiredguy

If you go to "supplyhouse.com" , they can supply you with a replacement gas valve. I would prefer a slow opening valve but I could not find any in stock. Valves in stock I looked at were Honeywell Models VR8200A2132- (1/2') or the V8300A4508- (3/4"). Both are for a standing pilot. Just pick the pipe size you have. I would set the manifold pressure to 3.5"WC. Before you remove the existing gas valve and Maxitrol regulator, check the gas manifold pressure at full valve opening as a reference point. If I were doing this boiler service I would strongly recommend that all the safety controls be updated or at least cleaned and serviced and that a relite gas system be installed and that the combustion be set with a combustion analyzer.

Megawboiler

THANK YOU! you were absolutely right. I will post a pic but the flame pattern at the partially open stage includes the tall and white flame coming from the secondary orifice beside the pilot light. I'm guessing this is the gas on the "wrong" side of the diaphragm? Will drill down on the rest of your recommendations and order the valve. Temps into the minus twenties lately so grateful for that manual on feature. I'm guessing that a new valve won't have that feature or...?

mattmia2

It having a manual override is part of what told me it was pre 1970s or so. You could run it off a battery and inverter for days or could replace the gas train with a millivolt valve and thermocouple with a thermopile and it wouldn't need ac power. Would need a millivolt thermostat and to make sure the other controls were millivolt compatible too.

Megawboiler

Great call on the white flame. Pics are normal pilot, then flame when manual override, then pic of partial flame from second orifice beside pilot.. I assume the partial flame is the gas that is leaking through the diaphragm? Will order new valve tomorrow but not worry about any "power failure" options. Will forward all other recommendations to my gas fitter.

ch4man

those old diaphram gas valves would open and close slowly.
your replacement valve should do the same. easy conversion for a good gas fitter

Megawboiler

Whew, big thanks. Two possible Honeywell valves. Liking the idea of slow opening especially since that's what I'm replacing. Is there that big a difference as the regular opening is in stock?
ALSO previous question was about the current filter and regulator replacement...(see pic above)....or does this valve replace everything?

rick in Alaska

Tim Mcelwain needs to get in on this. He will know exactly what you need. Are you out there Tim?
Rick

mattmia2

Look at what @retiredguy said. You don't need the filter. The regulator is part of the new combination valve. If he says the original valve is slow opening you want a slow opening replacement. If the individual parts of the burner are slow to propagate the flame from the pilot, which is a function of the basic design of the burner, you can get what is called delayed ignition with a fast opening valve, which is basically a small explosion every time the burner lights as the gas from those other parts of the burner lights.

Megawboiler

...and small explosions are definitely off my list of desired outcomes. Thanks for the answers...especially the ones I was hoping for. Supplyhouse.com won't ship to Canada but confident that with the correct part number I will be able to procure one. I'll keep ya'll posted.

Tim McElwain

You need to get rid of the entire gas manifold and install a Honeywell VR8300 A 4508 3/4 x 3/4 gas valve or the closest thing to it that Honeywell offers. That will replace everything on the manifold including the valve, regulator and combination main gas and pilot shut off. Plug the pilot shut off and leave the valve as your main gas shut off. Everything you need is built into the VR8300 valve. I would also clean the low water cutoff and then do a combustion analysis. That is a real oldy but should wok okay after you replace the existing controls and manifold.

Megawboiler

Thanks Tim. Trying to find Canadian supplier. The 4508 is not slow opening but the 4501 is, has same specs and has been recommended . Huge thanks for all the help on this.