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gas boiler, wont light, circulator pump running

cdestuck
cdestuck Member Posts: 17
I have a Weil McLain he2. quit working this evening so I looked and checked a bunch of thinks. The relay panel is a Honeywell R8335A 3 Zone. So with the thermostat calling for heat it feels like the pump is running as its warm. Pipes are all cold. The two low voltage lines that go down into the boiler, I found by jumping those terminals in the relay box that the boiler then functions. So at least I can have heat but have to hook and unhook the jumper to there terminals manually. Beside the terminals is a relay, burner relay. Its a OMRON LY1 12 VDC. So am I correct in thinking that this burner relay has gone bad? Is there a way to test this relay? Would trying to work the contacts with a 12 volt car battery work or would that kill a good relay? Boiler is about 20 years old. I sure hope I can find one of there relays locally if it is the problem. Tks for any hints, help, or advise.

Comments

  • the_donut
    the_donut Member Posts: 374
    edited February 2018
    Pictures of lines, panel, boiler and relays please. Low voltage lines I assume go to zone control and thermostat.

    Rating is 200,000 cycles and after 23 years you may be close to that. I would check switching voltage. Not sure of pinout.

    See if full voltage is there and amperage is under 15A load. If relay failed, you’ll want to know why. Otherwise new may fail after replacing.
  • cdestuck
    cdestuck Member Posts: 17
    Will post pics this afternoon. Not quite up to your level of expertise but we’ll see
  • cdestuck
    cdestuck Member Posts: 17
    Here’s a pic of relay control and then 2 pics of boiler. Here’s what is happening

    With therm calling for heat, circulating pumps runs, but boiler won’t light. I can get boiler to light by jumping the two terminals (red and white wire) to the rt of boiler relay at top of control.

    I removed the boiler relay to ck it for voltage. I get 37.4vdc. The relay itself is a OMRON LY1 12vdc. Should the 37.4 v be too high for the relay?

    Anothing I don’t understand is is the low voltage terminal bar on rt. Transformer feeds 27vac to the bar and I get 27v to each set of screws except the top to. That’s the thermostat calling for heat and I get no reading there unless I remove the wires then I get the same 27 v like the rest of the screws. Would a thermostat cancel out the readings st the screws?

    I have a spare boiler control that’s inside the boiler and I changed it with existing one and exact symptoms happen. Tks.
  • cdestuck
    cdestuck Member Posts: 17
    Pic of relay and pen pointing at two terminals I jump to get boiler to light.
  • JUGHNE
    JUGHNE Member Posts: 9,763
    Maybe the simplest thing first; does your T-stat need new batteries?
  • the_donut
    the_donut Member Posts: 374
    What’s the input voltage to the transformer? Voltage seems high across the board.
  • cdestuck
    cdestuck Member Posts: 17
    121v going in.
  • cdestuck
    cdestuck Member Posts: 17
    Can a transformer go bad in a way that allows higher voltage through. Could the 37v then blow the relay. Can I test relay with a 12v car battery?
  • JUGHNE
    JUGHNE Member Posts: 9,763
    The typical 120/24 VAC could put out 27 VAC unloaded, even loaded (working) will show higher than 24.

    The terminals you jump for boiler operation, is that a 2 wire cable that goes directly to your t-stat?
  • cdestuck
    cdestuck Member Posts: 17
    > @JUGHNE said:
    > Maybe the simplest thing first; does your T-stat need new batteries?


    I’ve tried bypassing the therm by a jumper in the box.
  • cdestuck
    cdestuck Member Posts: 17
    If the output of the thermostat is 27vac, what would then change it to the dc voltage. I see no other transformer in this box.
  • JUGHNE
    JUGHNE Member Posts: 9,763
    So where does the cable you jumper go to?
  • cdestuck
    cdestuck Member Posts: 17
    I just jump the one screw to the screw next to it. And boiler lights.
  • JUGHNE
    JUGHNE Member Posts: 9,763
    The wires connected to those screws.......what is connected to the other end of them??
    the_donut
  • the_donut
    the_donut Member Posts: 374
    edited February 2018
    I am wondering if bypassing the relay jumps past limit controls and pressure switch and goes straight to burner proved. Been searching for control panel pinout and relay configuration. No luck yet.

    Also
    JUGHNE said:

    The wires connected to those screws.......what is connected to the other end of them??

  • cdestuck
    cdestuck Member Posts: 17
    > @the_donut said:
    > I am wondering if bypassing the relay jumps past limit controls and pressure switch and goes straight to burner proved. Been searching for control panel pinout and relay configuration. No luck yet.
    >
    > Also The wires connected to those screws.......what is connected to the other end of them??

    Those two wires go down into the boiler and connect to wires that clip into the boiler controller
  • cdestuck
    cdestuck Member Posts: 17
    I’m going to just replace the boiler relay tomorrow if I can find one. They’re pretty cheap. If it appears the the whole relay controller needs to be replaced, what would be a good one for a 2 zone gas boiler?
  • the_donut
    the_donut Member Posts: 374
    Found a GV manual. Looks like that wiring goes to pressure switch from manual.

    Do a power cycle. Do any lights flash after rebooting?
  • JUGHNE
    JUGHNE Member Posts: 9,763
    Donut, that manual is not for his boiler. It is for the newer next generation that had a negative pressure gas valve.....he has atmospheric burners. I had the newer one myself.
    I would say there is no problem with his boiler, just the relay box.
    After re-reading his posting I see I did not pay attention the first time.
    He must have 2 t-stats and circs.
    If he kept the boiler jumper on, it should go off on the limit switch if the tstats are satisfied and pumps shut off.
  • cdestuck
    cdestuck Member Posts: 17
    Here’s a pic of schematic of the relay controller. Main input is 120v of course. The transformer reduces that to 24vac. Now what produces the dc voltage for the boiler relay? Wouldn’t that take a separate controller.
  • JUGHNE
    JUGHNE Member Posts: 9,763
    As far as DC used for control relay coil voltages;
    Some coils are rated for AC/DC.
    Sometimes if your digital volt meter is set for DC and you are reading AC, you get wacky readings.
    If they truly run on DC then there must be a rectifier built into the zone control board......I have never checked one out.
    (My system uses zone valves and the end switch turns the boiler on).
    I have noticed some electric furnace contactor elements using the DC relays. Why?? Can't use a stock AC coil if needed.
    cdestuck
  • JUGHNE
    JUGHNE Member Posts: 9,763
    No picture.....
    That AC/DC rectifier could built into a PC board within the zone control box.
  • cdestuck
    cdestuck Member Posts: 17
    Sorry, guess it didn’t attach. I get what you’re saying.
  • JUGHNE
    JUGHNE Member Posts: 9,763
    Do you see the diodes in the wiring diagram? The triangle with the line under them? They let the current flow in one direction only from power applied to one pump relay to the burner relay. But not allow that current to flow to the other burner relays, only to the burner relay.
    So consequently the burner relay needs a DC coil because it receives only DC sent thru the diode.
    Thanks for posting this, I have never seen and now understand more of the operation.

    The isolated contacts that go to the boiler are just a "dry" switch, it gets no power from the zone box. Just does the same job that you do when you jumper those screws.

    My best guess is to replace the DC burner relay.

    Just to show that an old dog nearly 70 can still learn something!
    cdestuck
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 12,004
    @cdestuck , you could look on line for that relay. Best bet is a WW Grainger if you have one nearby. You may have to convince them to sell to a homeowner. Just noticed the Honeywell part # on the dwg. so a Honeywell supplier can get one if not in stock

    Good job @cdestuck & @JUGHNE
    cdestuck
  • cdestuck
    cdestuck Member Posts: 17

    @cdestuck , you could look on line for that relay. Best bet is a WW Grainger if you have one nearby. You may have to convince them to sell to a homeowner. Just noticed the Honeywell part # on the dwg. so a Honeywell supplier can get one if not in stock

    Good job @cdestuck & @JUGHNE

    Will try to locate one locally monday and see how I make out. Need it quick so I can go to hunting camp. ha

  • cdestuck
    cdestuck Member Posts: 17
    cdestuck said:

    @cdestuck , you could look on line for that relay. Best bet is a WW Grainger if you have one nearby. You may have to convince them to sell to a homeowner. Just noticed the Honeywell part # on the dwg. so a Honeywell supplier can get one if not in stock

    Good job @cdestuck & @JUGHNE

    Will try to locate one locally monday and see how I make out. Need it quick so I can go to hunting camp. ha

    With the testing I did with my level of knowledge, I really thought it was the burner rely and looked all over our city and couldn't find one to try. Sort of resigned to calling my heating firm and bite the bullet. I looked a TACO relay panels online but was unsure which one to buy. Well the heating guy came out and I'm a bit disappointed in what his skill level was on this. We ultimately agreed that relay was the problem. So I called Grainger in Pittsburgh and having them over night me two. So I'll get back tomorrow if that fixes up my problem.
  • Tim McElwain
    Tim McElwain Member Posts: 4,506
    The Honeywell R 8335A is no longer made and was dropped from Honeywells line quite a while ago. The TACO series can replace it depending on how many zones you have as to which TACO relay.
  • Tim McElwain
    Tim McElwain Member Posts: 4,506
    Those OMRON relays are usually more available at electrical supply houses than heating supply houses.
  • cdestuck
    cdestuck Member Posts: 17

    Those OMRON relays are usually more available at electrical supply houses than heating supply houses.

    Tks Tim, we do have a pretty good electrical but I was getting pretty discouraged and gave up. So the new one is to be tomorrow. If it takes a panel I'd really like to do it myself to save some bucks and just because I like doing my own stuff. I looked on SupplyHouse.com. I have a two zone boiler, 2 pumps without zone vales. I wonder it they have any tech help that could help me pick out the correct one. Lets hope the relay does the trick
  • cdestuck
    cdestuck Member Posts: 17
    Hi guys. Well got the problem found and fixed. I received the new boiler relay and put it in place. A big fat NOTHING!! Pretty disappointed. . I pushed in on the relay a bit harder to make sure it was connected and heard a couple short clicks like the boiler was going to go. I thought then there might be a problem with the solder on the rear of the circuit board so I pulled all of the wires from the board, unscrewed the board from the metal panel.

    Began checking it over real well and found that the screw terminal block for the boiler relay had two pins that stuck through the C board and were soldered to the board. I could see there was a very tiny crack around the one pin in the solder connection. Did a resolder of both of the pins, replaced the board and the boiler is u and running. One of those deals where the repair was simple, finding it was crap. Thanks guys for all the help and suggestions.
  • JUGHNE
    JUGHNE Member Posts: 9,763
    Thanks for the feedback, glad you are heating again.
    cdestuck
  • the_donut
    the_donut Member Posts: 374
    Glad you found it. I thought the partial voltage reading was odd. Good to hear it is up and running and you have a spare relay just in case.
    cdestuck