New boiler, rollout switch keeps breaking

AlexV

Hi,
I have a new boiler Dunkirk DLX100 installed by Sears.
Problem is that rollout switch keeps breaking and stopping the heating. Normally it takes about 30 minutes for this to happen. As soon as I reset the switch, it works for another 30 minutes.
I installed liner in the chimney but it did not help.
People from Sears are clueless.
I tried running boiler with nearby window open but it did not help either.
What is causing this? I suspect it is the switch itself - if it was really flames heating it, I think it would not run for another 30 minutes as soon as I reset it. Any thought on how I can troubleshoot this?

Alex

Steamhead

Call a pro. Where are you located?

AlexV

I am in Northern NJ

Steamhead

Try @Dave0176 , @EzzyT or @JohnNY . Can't go wrong with them.

JohnNY

Sounds like a carbonized boiler to me but would have to check it out. How old is the boiler?

AlexV

It is new boiler.

JohnNY

Then Sears ought to make good on it. I'd have to take a look to see what's going on. Call if you'd like. My information is below.

AlexV

So far they have no clue. Should I just ask them to replace the unit?

JohnNY

Well, you're certainly entitled to a working boiler since that's what you paid for. Where are they now with this? What are they offering/telling you?

AlexV

They told me that I have draft issues and recommended to put a liner in the chimney. It did not help.
I am trying to figure out what to expect when they come again.

JUGHNE

When they come again, you could ask them for the printout of the combustion test done on the exhaust gases which would include the draft.

Also what the manifold gas pressure is and could it be overfired?
So they would want to clock the gas meter to check the firing rate.

Do you have deer in Northern NJ? Are you familiar with the "deer in the headlight" look?

AlexV

Yes, we have deer in NJ
The old furnace was 150K and new one is 100K. Is it possible that they did not change the firing rate?

JUGHNE

By over firing I mean that the gas pressure to the burner orifices, down stream of the gas control valve, could be set to high. This would produce more fire than the boiler is rated for.

Could you post pictures of the boiler and piping around it, including pumps if any.

AlexV

Mark Eatherton

This boiler is about as simple s they come. Just to clarify, there are two devices on this boiler to protect against flue gas spillage. One near the base of the burner is a fusible link device that is not resettable. The flue gas hood SPILL switch is a manual reset device. I suspect your problem is with the upper, resettable spill switch.

Can you feel any spillage coming out of the draft hood? Or better yet, make some smoke and see if it is drawing air INTO the hood, which it is supposed to. It can be something as simple as a cold chimney, on an outside wall that has a problem establishing a good draft to evacuate the byproducts of combustion. Or, it could be that the corrugated (assumption on my part) liner is undersized and incapable of establishing a proper draft.

How high is the chimney?

Is it located on an outside wall or an inside setting?

How large and what type of liner was installed?

Was a combustion analysis and draft test performed?

If not, why not?

Was the previous boiler also doing the heating of your DHW? If yes, with a side arm tank or with a tankless coil?

How large was the previous boiler (BtuH wise)?

Answering these questions will cause us to ask more...

ME

AlexV

What is weird is this -
1. the switch trips after boiler runs for ~30 minutes
2. I reset it in in a few seconds and boiler resumes and runs again for another ~30 minutes

If it was overheating, I would expect that the switch would trip immediately after I reset it because boiler is still hot, but It is not happening.
Does it mean that the switch is faulty?

JUGHNE

Could we see the boiler from the back side, include the back side of the pump, please.

AlexV

Mark,

The bottom switch is the one that breaks.
Both upper and bottom are resettable.
I see pretty strong air flow at the air intake of the burner. I also see some weaker flow towards the hood.
I need to ask if they peformened combustion analysis and draft test.
Chimney is about 15 feet high.
Liner is stainless steel, 6". Chimney is outside, bricks.
Old boiler was doing only heating and it was 150K, new one is 100K.

EBEBRATT-Ed

Have you been at the boiler when it trips? Can you verify that the stack damper is open? Does it trip while running or when it shuts down?

AlexV

It trips then the damper closes.

delta T

My first thought would be combustion air, but you mentioned that you ran it with the window next to it open and there was no change....Would have to check the combustion numbers, mostly manifold pressure, as stated above to check if the boiler is being overfired. This is your next step for sure. Call one of the pros that were mentioned above and get a combustion analysis done, and if the installers did not do one, ask them why not....this is standard procedure for any new boiler (well it is supposed to be anyway). Look in the installation manual and find the section about start up, there should at the very least be something about checking and setting the manifold pressure.

JUGHNE

For your 30 minutes of run time how well does it heat the house? There should be an arrow on the pump, could you post a picture of that, including the back of the pump.

My wacky theory is that if the pump is installed backwards, it would pull the hot water out of the bottom of the boiler.
This would not be effective in removing the heat from the water, consequently also not removing heat from the burned exhaust gases that the cooler water entering the bottom are supposed to do.
just a WAG.
It may heat your house somewhat.

Also what is the high limit temp setting for the boiler water?

AlexV

It heats pretty well in 30 or so minutes. I will take a picture a little later. The high temperature is set at 210 but it rarely reaches that - most of the time it trips around 190.
Again, what is weird is this: why after reset it continues running again for another 30 minutes? I would expect it to trip again very shortly, given that everything is already hot.

delta T

@JUGHNE I think you may be onto something with the water temp.

Default position for the motor on the 007 (writing up) is to pump down, so unless they spun the motor it should be pumping correctly (though its always a possibility).

I do wonder if they set the high limit to 210 or so, wouldn't be the first time I've seen it. That could explain the 30 delay in the switch tripping, though maybe not the second 30 min delay after it's hot....

This one has me scratching my head, but then again, a monometer would tell us a lot more......

Tim McElwain

I would bet on a poor draft condition that with the higher input boiler was not as issue as the chimney (only 15 feet) and an outside one to boot is not always creating enough draft. Draft is created by Delta "T" temperature difference in the flue and height of the flue adding the flue liner may have actually made it worse if the size was reduced.
You need someone to look at this who is a professional and also understands combustion issues. You are creating draft and then losing the draft. That will explain the 30 minute delay. I would hook up a draft gauge and combustion analyzer then sit down and watch it for an hour to see if you make it do what it is doing. That will give you draft and also stack temperature. Keep in mind flue liners have 20% less capacity than a double wall type "B" vent

Tim McElwain

I just looked at your picture and noticed a vent damper is on the unit. Try removing it and run the boiler without it. Just insert a piece of flue pipe in place of the damper. If it does not fail then install the damper back in and try it. If it fails the damper may be the problem as it may be restricting the flow of combustion products causing spillage. It looks like a Field damper but not able to tell from the picture. We need a picture taken from the front of the boiler.

AlexV

I have Dwyer Air Meter Kit, 460, .005-1.0" w.c:

https://www.amazon.com/Dwyer-460-005-1-0-260-4000-Carrying/dp/B009P8OKVS/ref=sr_1_1?ie=UTF8&qid=1510617468&sr=8-1&keywords=dwyer+460+air+meter

Can I use it to measure draft?
If so, how?

Noel

2015 NFPA 54 page 54-100 or 2009 NFPA 54 page 54-100 shows venting tables for this application.

JohnNY

AlexV said:

I have Dwyer Air Meter Kit, 460, .005-1.0" w.c:

https://www.amazon.com/Dwyer-460-005-1-0-260-4000-Carrying/dp/B009P8OKVS/ref=sr_1_1?ie=UTF8&qid=1510617468&sr=8-1&keywords=dwyer+460+air+meter

Can I use it to measure draft?
If so, how?

Yes. You can use that draft meter. I've got the same one from years ago.