Oil Burner Issues

[Nedly]

Our furnace has had issues for over a year now, and now that we are over 200$ in it still is not working right.

I can get any info that is needed. It runs off of diesel. It fires up, runs for a good 15 mins, then it will not start again, all the while the control box is calling for heat it just does not fire up. Replaced the CAD sensor, replaced the intermittent igniter several times because the first couple were defective, we replaced some other massive control board (the one with error lights etc), replaced the ignition base plate etc, replaced oil filter, checked fuel in tanks, replaced nozzle, then we replaced the copper tube from the tank to the boiler because the original was under cement and we had theory there was condensation.

There is no thermostat, it is jumped so once power is on it is in constant call for heat. We also checked the control box to make sure it was not in a lock out mode. I checked the manual schematics and could not find anything as far as sensors for air / draft, temps, etc, and am not sure how to test any of those...

It is the AF/AFG Beckett Model. We got one of the more basic honeywell igniter boxes.. So I went as far as watching instruction videos on burners and how they work and I still cannot figure out what is wrong. It seems to be some sensor or control board issue as far as I can tell. There is absolutely nothing that happens when it is trying to turn back on after the 15 min run, it just sits there dead, but while it does the reset is down and it is in call for heat...

 

[BoilerMan]

Welcome to hearth.

Does it light well on the first call for heat?

If you remove power and reconnect does it start as normal?

TS

 

[Nedly]

Yes on both. It fires right up initially and runs fine then will not come back on. If powered off and on it will fire up, run the one cycle and then not fire again. I am leaning towards the intermittent igniter board. I had my doubts that it was that because we have replaced it three times now, it seems every darn one is defective...

 

[Nedly]

This is the control system we got.. http://www.amazon.com/Honeywell-R81...r=8-4&keywords=honeywell ignitor intermittent

This is the one I am thinking about getting.. http://www.amazon.com/Honeywell-R81...keywords=honeywell ignitor oil burner control

 

[ewdudley]

With the T-T jumpered I'm assuming the burner cycles off on high limit. Does the circulator continue to run after the burner cycles off? Can your force the burner to re-light temporarily by jumpering across the high limit terminals of the aquastat?

 

[DBoon]

For oil burners, I think you would get more responses as https://heatinghelp.com/

 

[Nedly]

I have to scratch a little of what I said. We re tested it, it seems like there is a reset getting tripped or something. Even after poweroff/poweron it will not fire back up unless we wait several hours..

 

[Nedly]

With the T-T jumpered I'm assuming the burner cycles off on high limit. Does the circulator continue to run after the burner cycles off? Can your force the burner to re-light temporarily by jumpering across the high limit terminals of the aquastat?

You lost me there a little bit. I know a little about the boiler but that sounds like gibberish. What are the high limit terminals? O I was looking up that a min ago, the aquastat, they said to test it with a volt meter....

 

[Nedly]

For oil burners, I think you would get more responses as https://heatinghelp.com/

Thanks I am checking that out now..

 

[STIHLY DAN]

ad circ pump. It gets up to temp but can't get the heat out, when the chimney sucks the heat down it restarts.

 

[Nedly]

I think I might be onto something now. I found a forum suggesting to test the L1/L2 and B1/B2 terminals on the aqua-stat to test and see if either the low water cut off or aqua-stat were having issues and I got a zero reading on the L1/L2 pointing to the low water cut off, but I got the full reading of 120vac on the B1/B2 terminals...

 

[R Mannino]

I'm guessing a bad motor on the burner. With power at B1 on the aquastat the burner should be running.

 

[Nedly]

How could I test that? Is it by jumping the high terminals on the aquastat? I am willing to do any troubleshooting i am just not sure what to do.. When I tested the unit the power was on but the machine was not running. I tested B1/B2 and got 120vac, but then nothing at L1/L2. I read that could mean the low water cut off is messing up. So I looked at that and it seems to be just a transformer, some resistor and a sensor...

Would the burner run for initial runs if the blower motor was bad? Because it will start and run for a while after it has sat. It seems to finish a main cycle versus get interrupted (seems)...

 

[R Mannino]

How about some photos of what you have going on, then it won't be such a stab in the dark. Like of the controls and such with the covers off.

 

[BoilerMan]

Yes pics mean 1000 words. Some of us here do this for a living.

TS

 

[R Mannino]

No photo's here either http://forum.heatinghelp.com/discussion/152009/burner-issues-wont-re-fire#latest

What model # aquastat and LWCO and how is it wired?

 

[Nedly]

Sorry about the delays. I do have more model numbers and pics I am congregating now and will post. Current update is we drained the low water cut off and shut off its water supply and then tried to start it, it did not work indicating the low water cut off should be fine. We never did get a reading on the L1/L2 terminals. We also noticed that if we raise the temp setting in the aquastat that it does heat up to that temp and then shut off, then no refire. I have no idea if it does have something to do with the fact that it is forced hot water setup or not. I know someone mentioned there being two parts.

 

[STIHLY DAN]

Sorry about the delays. I do have more model numbers and pics I am congregating now and will post. Current update is we drained the low water cut off and shut off its water supply and then tried to start it, it did not work indicating the low water cut off should be fine. We never did get a reading on the L1/L2 terminals. We also noticed that if we raise the temp setting in the aquastat that it does heat up to that temp and then shut off, then no refire. I have no idea if it does have something to do with the fact that it is forced hot water setup or not. I know someone mentioned there being two parts.

CIRCULATOR PUMP is not running.

 

[Nedly]

Ok, so I am starting to understand this all a little bit better. One question, are the fazes of high limit and low limit where the furnace heats up to temp (high limit first faze), then the low limit is the water heating process (low limit second faze)???

That is exactly what it is doing!! It is running through the high limit cycle but then not moving on to the low limit cycle. What does this mean? This is what someone else mentioned but I am still trying to make sense of it..

" jumping the thermostat isn't how to make hot water, its the low limit in the controls that decides when it turns on from the aquastat in the domestic coil. If you are not using it for heating the boiler could be hitting its high limit and not turning back on at the low limit, with no low limit set int the controls. "

I have more news too. I guess the setup is that the forced hot water was never shut off, rather the "house" based thermostat has been turned all the way down so it does not call for heat. So should I turn that up and shut off the feeds in the line?

 

[STIHLY DAN]

High limit shuts boiler down, if there is a call for heat the differential say15* kicks in. If there is no call for heat the boiler will sit idle till it drops to the low limit setting, then fire back up. Have no idea what "forced hot water was never shut off" means

 

[Nedly]

I get what you mean. I am really new to a lot of this and am just now reading about the different coils and the setup. At this point I am just trying to figure out what is going on so I can get hot water. Someone else is suggesting the setup is messed up because of "two sets of coils"? something about an internal coil and a domestic coil. Basically I am trying to run this unit to heat up the tap water setup and not the forced hot water setup and I am not sure what is going on at the moment.

So it is running right? but....I need to do something more for hot water? This here is where I am stuck.

 

[STIHLY DAN]

domestic hot water set up have a tank or just a coil in the boiler.

 

[mustash29]

If you have a tankless DHW coil in the boiler, you should have a tripple aquastat. That will operate off the low limit setting to keep the boiler warm 24/7 in order to provide adequate heat for DHW should you turn on a faucet somewhere. When the low limit is in control, the circulator (and zone valve flows) are disabled. This provides simple priority control for making DHW.

When a zone calls for heat, the boiler will heat up to the hi limit setting and hang out up there while it satisifys the space heating demand. When the zones are satisified, temp will drift down (heat loss up the flue pipe) untill the low limit takes over to maintain minimum temp.

This is a long read but gives a lot of details. The thing to stress is that when playing with the settings, the hi & low must be about 20 deg apart, so they don't interfere with each other. If they are less than 20 apart, funky stuff can happen.

(broken link removed to http://inspectapedia.com/heat/Aquastats.htm)

 

[maple1]

Hard to tell from all the back & forth, but it sort of sounds like there might not be anything wrong with the burner and it's working as it should per aquastat settings. Still light on details though, such as exactly what is there for stats, and what they're set at, boiler temps when things start & stop, and exactly what starts & stops then (burner, pumps...)...

 

[mustash29]

For example, I have mine set up like this:

Hi limit set to 170, it has a built in negative 10 differential, so it fires from 160 to 170 during calls for heat.

Low limit set to 140, it has a built in neg 10 diff, so it maintains 130 - 140 when there are no calls for heat.

The 3rd setting is the variable differential, which only affects the low limit. When it is set to the minimum 10 and 140 like above, it maintains 130 - 140. If I dial the diff up to a max of 25, it will still fire at 130 but heat up to 155.