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Polaris PBCG gas valve replacement

gjh42
gjh42 Member Posts: 10
edited July 2022 in Domestic Hot Water
I have a 25 year old Polaris PBCG water heater (1997), 34 gallon, 100MBH propane. It has worked great for most of that time with a few ignitor replacements, but recently started failing to ignite and locking out while I was away, not good in winter when it heats the house. Now it never runs properly, always shutting off with a 3-flash error code (failure to ignite). It seemed the ICM was giving the burner only one second of opening before shutting off, so I got the correct replacement for the model (UTEC 1018-524). It now seems to give the exact startup intervals it should, but still locks out with the 3-flash error. The gas control valve for PBCG is discontinued and I have not been able to find one anywhere including ebay. Is there any gas valve that can be used to replace this model? I would hate to throw an expensive and otherwise good heater away, not to mention the hassle of installing a new one in the confined space I have.

Comments

  • hot_rod
    hot_rod Member Posts: 18,254
    How long do you think the tank itself is going to last? It’s not a matter of IF the tank will leak, but when. Sooner or later you will need to go to plan B, maybe now is the time before you dump more $! Into it?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • gjh42
    gjh42 Member Posts: 10
    Being all stainless steel, I thing it has quite a few more years in it. A replacement gas valve for a couple hundred dollars is a lot easier than replacing the heater and reconfiguring all the connections in a very tight space.
    Is a "universal" replacement gas valve inherently going to cause any problems? I found this one https://www.ebay.com/itm/161887422152 (36H32-214 White Rodgers Heating Furnace Electronic Ignition Gas Valve 24V) which is set for 100MBH and1/2" NPT connections, like my heater. It is straight-through rather than rear outlet as the original is; is it bad to add an elbow to make it fit between my gas supply and the blower?
  • Larry Weingarten
    Larry Weingarten Member Posts: 2,785
    Hi @gih42 , There is an independent parts house I deal with, and they have always had answers for me when nobody else did, and they seem to be able to find nearly anything. Call Mack Stove at 831-899-7278 and ask for Dan or Mike. See if they can help. They just helped me with finding a gas valve for a forty year old commercial State water heater.

    Yours, Larry
    ps, I trust your water is low in chlorides? ;)
    kcopp
  • hot_rod
    hot_rod Member Posts: 18,254
    I’m pretty sure the Polaris uses a negative pressure gas valve. As the blower ramps up and down it pulls the gas and blends it for the burner. That is how the burner modulates. I have never seen a universal replacement valve like that. I think you want to find an OEM valve.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • I believe they are made by American Water Heater Company. One of these numbers should work and if you give them the serial and model numbers, they should be able to source a gas valve for you.

    (800) 456-9805
    (800) 999-9515

    I have a few of these on my route and they seem hang in there. The igniters seem to last longer when you turn the temperature up.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour
    kcopp
  • gjh42
    gjh42 Member Posts: 10
    Yes, the Polaris wants a -.02" w.c. manifold pressure. I don't see enough information on the universal replacements to know if they would accommodate that.
    Thank you for the various recommendations on contacts for OEM units. I will update when I have more information.
  • gjh42
    gjh42 Member Posts: 10
    I have recently read that ignitors fail quickly below 140F settings; I have kept mine around 120 F, and ignitors have lasted 6-8 years on average. I have replaced it three times, most recently just a couple of years ago, and I still have another spare on hand.
  • HomerJSmith
    HomerJSmith Member Posts: 1,927
    Polaris had a program where they would supply parts for free to replace original faulty parts. One would get a new blower, control board, igniter and a few other things.

    You might qualify, I would contact them. Supply them your model and serial #.
  • @HomerJSmith After 25 years?
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour
  • hot_rod
    hot_rod Member Posts: 18,254
    Numerous places sell those old Polaris parts, gas valves seem to be out of stock at all the places I looked. So either back order or no longer manufactured?

    I think you can still purchase new Polaris tanks? It was a sweet radiant heat source, at a good price

    One or the large online radiant suppliers sold them as combined open systems for many years.

    Original purchase price divided by 25 years of high efficiency performance. It shouldn’t owe you much😙
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • The older ones had a small, non-adjustable differential on the operating limit and they would short-cycle like crazy. The new ones corrected that. 
    Working on the gas valve, blower or even changing the igniter meant that you were flat on your stomach with your arms reaching inside with your tools. It was even tough when I was a young man and never looked forward to it. 
    But they performed and lasted. 
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour
  • HomerJSmith
    HomerJSmith Member Posts: 1,927
    Alan, it was a liability issue. A liability issue follows you forever or until the company goes belly-up. I would check with Polaris.
  • gjh42
    gjh42 Member Posts: 10
    The manufacturer couldn't even find records of my serial number, said it was invalid. They finally figured it out, and said they couldn't help me, period. All they could do was give accurate part numbers (old # 6907310, newer # 100093698) to search for online. Of course nobody has one. I called Mack Stove and he said he would look into it and call back... no word yet.
  • gjh42
    gjh42 Member Posts: 10
    The lowest priced new Polaris is over $4000. I seem to recall I paid around $1800 for a similar (34 gallon) one in 1997. I was never able to run it out of hot water even in winter.
  • GGross
    GGross Member Posts: 404
    Have you tried entering the serial number into the parts list portal?
    https://eportal.hotwater.com/Commerce/PartsList#web-app

    AO Smith/American are the same, I do believe that polaris was a model by American Water Heater. Neither part number you listed comes up as something I have ever stocked before, I don't think we ever sold any Polaris models though
  • ratio
    ratio Member Posts: 3,336
    Negative pressure gas regulators aren't that uncommon, Trane for instance uses them. I can't imagine that it's discontinued, but maybe they don't OEM them anymore. Have your tried the manufacturer of the valve itself? I'm sure they'll tell you they don't have that particular one, but they have have one that will cross over.
    Larry Weingarten
  • HomerJSmith
    HomerJSmith Member Posts: 1,927
    edited July 2022
    I have a brand new Robertshaw 7200DERN gas valve for Polaris on the shelf, imagine that. I don't know what the current value is. Send me a e-mail and we will negotiate.
    GGrossgjh42
  • gjh42
    gjh42 Member Posts: 10
    Boston Heating Supply, Zoro, and every other supply house I could find all say the Polaris gas valve for my heater is discontinued and they don't have one. Nobody on eBay says they have one either. I couldn't find information on the actual valve manufacturer, so if it is a Robertshaw unit, that is good news.
  • HomerJSmith
    HomerJSmith Member Posts: 1,927
    It is! It is as I described.
  • Larry Weingarten
    Larry Weingarten Member Posts: 2,785
    Hi @gjh42 , Have a look at this link: http://bostonheatingsupply.com/polaris6907310.aspx Look to the third picture and when you scroll over it, you'll see the brand and model number. Is this valve that you currently have? If so, PM Homer J Smith and get that one he has!

    Yours, Larry
    Alan (California Radiant) Forbes
  • HomerJSmith
    HomerJSmith Member Posts: 1,927
    edited July 2022
    The threaded two ports on my valve is the same as pictures 3&4 in Larry's post to Boston Heating. The others are blocked. Mine is a Polaris supplied valve so, gjh42, it must be the same as yours.
  • gjh42
    gjh42 Member Posts: 10
    I was able to get a mirror behind the gas valve and confirm that the label on the back says 7200DERN. Robertshaw says that valve is discontinued, but somebody on eBay has a new one for $95 plus shipping (they obviously don't know that is a replacement for a Polaris unit).
  • HomerJSmith
    HomerJSmith Member Posts: 1,927
    BUY IT!
  • gjh42
    gjh42 Member Posts: 10
    I found a website (surpluscityliquidators.com) that has 40+ of this valve for $76 each ($91 total with shipping)... turns out it is the seller of the one on eBay :D
    It's on its way.
  • gjh42
    gjh42 Member Posts: 10
    Much struggle and searching later... I received the gas valve... it is a match for my old one except that it has only a straight-through outlet, not the back outlet option that my old one uses. This would require running the gas supply in the access opening rather than through the sidewall of the pedestal enclosure. I have talked to numerous local plumbers, the individuals were either scared to work on it or never returned numerous calls, and the companies refused to work with my customer-supplied equipment even though they couldn't have gotten one from the manufacturer either.

    I checked the rest of the wiring and connections and found the white wire from the main feed had a bad spade connector which I replaced, and now I get 26 volts at the gas valve instead of 15 volts. Still doesn't work.

    I am about ready to replace the valve myself, but need to know if the factory replacement would be set for natural gas or propane, or is agnostic. Nobody including tech services at Robertshaw can give me any information whatsoever, nor is there any indication of gas type on the valve body. The valve is assembled with tamperproof screws, so if there is a conversion to be made it must be associated with one of the threaded inserts on the top or ends of the valve. Does anybody know whether this valve needs to be converted, and if so how it would be done? I have converted burners to propane before so am not worried about that process if I have to do it.

    The original has a 1/8" aluminum tube running from the 1/8" NPT connection labeled "vent" to the burner, while the new one has a sheetmetal cap inserted in that location (a shipping cover that pries out with thumbnail pressure). Next to that is a 1/8" NPT plugged connection labeled "out press" (perhaps for testing, or for adjustment?). These are above the 3/4" NPT gas outlet.
    There are labels cast into the body for "pilot" and "pilot adj" but I think these are irrelevant to me.