Weil McLain GV-3

OJay

I have an old WM gv-3 boiler that will not ignite. Igniter lights up, gas valve clicks on, and igniter doesn’t ignite. It locks out after its 3 attempts. In the past year I have replaced the whole blower assembly because it went bad. Replaced igniter and also cleaned the inside of the heat chamber with a vacuum. I have followed the troubleshooting charts listed in the manual for the boiler. I went ahead and put a new control module on it 2 days ago because I like to waste money and it’s getting cold in Ohio. We have a wood burner so I’m not to cold.  The new control module didn’t help solve the problem and it actually has a new blinking light that the old module never had blinking. Now the limit control light blinks on the new board right away. I followed the chart for that light also. So as far as I know it could be the limit control switch and temp sensor need replaced or a new gas valve according to the troubleshooting pages. I’m looking for help from anyone who may have real experience with these boilers and my problems I am having with it. Also, could the exhaust flue be partially clogged? I can feel air coming out of the bottom of the blower assembly when I remove the hose, so it seems that enough is flowing through the exhaust and through the boiler. And yes the intake pipe has no clogs. Thank you in advance!

EdTheHeaterMan

Will need to know more information. There are at least 4 versions of the GV boiler. What series is yours

By the way...if your boiler does not have a series number then it is probably a series 1, they will only give you a series number for series 2 and newer.

Ironman

The only way to test the gas valve is with a voltage meter connected to the terminals to see if 24v is present during the 4 second window that the valve is energized for ignition. Also, connecting a manometer to the manifold pressure tap will confirm if the valve is opening.

Randomly replacing parts is expensive and not the way to correct a fault. Proper diagnosis is required.

EdTheHeaterMan

Ironman said:

Randomly replacing parts is expensive and not the way to correct a fault. Proper diagnosis is required.

I thought this is the only way to get DYI home owners to decide to call a pro.
When there is air in the radiators and they don't get hot.

Homeowner repair Logic

1. The thermostat is set at 70 and the room is only 65.. replace the thermostat
2. After that does not fix it, then follow the thermostat wire to the boiler and replace the control that the thermostat is connected to ( since the thermostat is obviously not the problem the thingie the thermostat is connected to must be bad.)
3. After changing that with no improvement in resolving the problem, then just replace all the parts that are connected to the control you just replaced.
4. Now that you are totally frustrated, and out about $600.00 in unnecessary parts that you can't return (because most electrical parts are not returnable even by professionals) Homeowner decide to call the plumber or heating guy,
5. He comes in and charges you $150.00 to let air out of the radiator which only takes 15 minutes and Homeowner complain about his high prices, which only confirms that the homeowner should try to fix stuff without the help of a professional.

Mr.Ed

PS, I'll still be glad to assist if I know which GV boiler this homeowner has.

OJay

It is a series 1. Thank you for any help. Just wanted some knowledge on common problem with these. That’s what forums are for. 

EBEBRATT-Ed

@OJay

Your first post says the "Igniter lights up, gas valve clicks on, and igniter doesn’t ignite" so do you mean the ignitor sparks but you don't get gas? Or the igniter doesn't spark?

As @Ironman said your going to need a test meter to see if your getting power to the gas valve. And a low pressure gauge or manometer that measures in " of water collum to start checking this out.

As far as the flue goes if you think it could be plugged take it down and clean it out. No one here can troubleshoot that without seeing it

OJay

The igniter glows and does not ignite a flame when the gas valve clicks open. I asked about the flue to see if anyone knows if that is a possible problem with these boilers. I know I can take it down and check. That would result in breaking seals and possibly damaging the pipe so I was just asking  a general question. I really am just asking for some possible helpful information. Thank you. I know I can call a repairman, I thought I would try this forum as it has a lot of helpful replies to people’s questions. 

EBEBRATT-Ed

@OJay

If the igniter glows and the gas valve clicks then you mostlikley have a bad gas valve or no gas. Do you have other gas appliances water heater, stove or dryer? And are they working?

EdTheHeaterMan

The sequence of operation in your boiler is
1. Call for heat to the boiler from thermostat (or zone control if more than one zone)
2. Combustion / vent fan operates
3. Once the fan is up to speed (seconds) the pressure switch registers the fan operation and electrical contacts close. this sends a signal back the the control.
4. Proof of air flow will start the ignition cycle
5. Hot Surface Ignitor (HSI) will glow orange within a few more seconds and will get brighter over the next 30 Seconds. You can view thru the observation port)
This is from page 17 of your manual

6. Once the HSI glows for the preprogramed time, the control will power the gas valve to open.
7. After flame is established within 4 seconds the flame sensing circuit will inform the control that ir is ok to allow the gas valve to remain open.
8A. If the flame sensor does not sense the flame the control de-energizes the gas valve and the flow of gas will shut off
8B. The gas valve will continue to flow until the call for heat is over, the high limit is reached or a different limit or safety device interrupts the signal the the gas valve.

i have a feeling that there is a flame sensor problem. This is a very common problem with this boiler

JUGHNE

I had this boiler in the past as a series 2 model.

Seldom a problem, had to change the board and maybe the hot surface ignitor.

The hot surface igniter also acts as the flame sensor.

The flame sensor system requires a good ground from the burner back to the board.

This return ground is thru the metal of the burner, the only ground connection I can see for the burner is on the blower. The ground wire would then thru the blower wiring harness back to the control board.

When you changed the blower are you sure the ground wire did not get disconnected?

The ground wire from your house power supply must be solidly in place.

Another standard maint item to look at are the hoses that go to the collection box.
remove them one at a time to insure they are not full of water and the collection box has no water in it.

Also there is a flex hose trap on the exhaust pipe, that must be clean.

Docfletcher

I'm not a pro, I have a GV4 series 3, it sounds like an air flow issue to me. You may have debris in the two holes on the inducer underside. I would remove the two hoses and use an Allen wrench and some air to clean out the holes. If it ignites OK then... You might consider cleaning out the inducer assembly properly. Also I'd remove the fresh air intake just to see if it helps. Be sure to replace the fresh air intake afterwards.

OJay

Thank you everyone. We are still trying to figure this one out. Had a tech here. The igniter is shutting off right when the gas valve opens and it’s only staying open for about 4 seconds. He is thinking flame sensor problem as well. It has a brand new igniter from two weeks ago. I have check all hoses and grounds. I did drain water out of the flex hose on the exhaust. Gas pressure coming into the gas valve is normal. 

OJay

Update, I decided to go mess with the igniter and with the little bit of wiggle room it has, i repositioned it and it’s igniting a flame now. I also crimped the female ends of the igniter wiring harness so they would fit a little tighter when plugging the igniter in. Hopefully it’s good to go. 

Castle

I have a GV3 Series 2 with the same problem and a new igniter. Early on in its life I had to replace the control module, I think. (I actually have six of these and the control module had to be replaced early on in three or four of them. Since then whenever one goes down it almost always is fixed by replacing the igniter. A different one had to have its blower motor replaced and the pressure switch with the two hoses that I assume let it know whether the blower motor is working well enough.) Anyway, I am in the same situation as you with the current problem one and wonder if it's still working for you.