Dunkirk Q90-100 - Blinking Valve Light

jcurry5

I have a Dunkirk Q90-100 boiler that was working but I noticed there was no more hot water.

I took the cover off and saw that the IBC has the Valve light blinking. I power cycled the boiler by turning the breaker off to it and turning the gas valve off (Honeywell), waited 5 minutes, and turned the gas to ON and turned the breaker back on. However, same blinking Valve light.

The initial startup goes through 3 times trying to ignite and get things going but then it fails on Valve.

The manual states:
IBC IS LOCKED OUT. PROBLEM IS FLAME HAS NOT BEEN PROVEN IN
THREE (3) IGNITION ATTEMPTS. MAY BE DUE TO BROKEN IGNITER OR
LACK OF OR LOW FLAME SIGNAL, OR NO GAS

I don't know very much about boilers but I can't see where the igniter is. On the front of the boiler unit, it shows 0 pressure (negative pressure?) as the needle is all the way to the right.

My assumption was there might have been a blockage on the intake/exhaust PVC on the outside but that looks clear from what I can tell. I didn't try to vacuum anything out, just a visual inspection. My other assumption was that seeing there's no pressure, no gas is getting fed into it but I can't tell where or how that could be a problem.

I tried googling this but it seems like a lot of folks don't like working on these systems so any help would be greatly appreciated!

109A_5

Hello @jcurry5,

Assuming your unit has the Hot Surface Igniter was its operation verified ? An Orange glow through the observation port on the boiler block.



See documentation on this page, it may be in addition to what you have, scroll down,

https://dunkirk.com/product/condensing-gas-boiler-q90/

jcurry5

After reading this, I suspect it is the igniter that's failing.  I'll check it out.  Thanks.

mattmia2

What pressure is at 0? Can you show us a picture? Is this a hot water or steam boiler?

GGross

Yeah I am curious about that pressure as well, could have a low water cut off that is tripped

mattmia2

(i suspect it is steam and the 0 psi is normal). If it is showing an error it is either failing to ignite for some reason or failing to sense that it ignited.

109A_5

@mattmia2 and @GGross, as much as I also think the pressure being at 0 seems odd and may also be a separate independent system issue, with the boiler's wiring diagram and the Hydrolevel 3000 manual I could not find any sensor that would shut the boiler down with just only low water pressure (some boilers do). And also flash the VALVE light. The only pressure switches I could find were combustion related. With production changes and documentation not being updated anything is possible.

Although with the OP's description a high temp lockout did not seem to be the case.

mattmia2

Looking for that specific model, looks like it is hot water only so the 0 psi thing is something you need to figure out before you fire it so you don't dry fire it. Don't think it is the combustion control error but it is a serious safety issue.

ZackR

Even though this is an old/dead thread, I wanted to add some info, because when I had been having troubles with my Q90-100, I also had difficulty finding useful info.

The area circled in red is where the ignitor is. You can look in the little circle window above to see if the ignitor is getting red during the normal start up sequence. If you don't see it glowing or don't see anything at all, the ignitor is probably broken.

If you see it glow and the boiler fires for 5-6 seconds, then turns off, you have a flame proving issue. Flame proving is done through the ignitor. The manual states you can try to brush off the ignitor, but they are super fragile(as me how I know).

You can also remove the burner and clean that. A burner caked with junk can effect the flame proving. I had intermittent proving issues until I gave mine a good cleaning.

As others have said, you'll need to figure out why you have zero pressure. Do you have any noticeable leaks?

Hope this helps some one

twistedmetal

Any resolution?