Oil furnace cycling Q?

[BobMCT]

I have a Weil-McLain oil fired hot water furnace which is cleaned and "tuned up" each year by our svc company.

This year it has started short cycling. By that I mean that it will start and run for about 15-45 seconds then stop. A few miniutes later it will do that again. It doesn't sound like its failing and stopping, just stopping normally.

I am assuming there is some part or component that may be causing this but because I'm not a furnace guy I thought I would ask here before I dig further. We do have four zones plug a hot water heater connected, each with a separate thermostat.

So, any suggestions as to what it might be?

Thanks

[harry]

Get whoever serviced it back. This is not normal.

[notbob]

Why are you aking us instead of your "svc company"?

nb

[BobMCT]

Because as many, many posts here demonstrate, it's near impossible to find a "good" svc company. It seems that when a good one is found either a big one swallows it up or it/he goes out of business.

That last time I had a problem I had the svc company out three times with three different guys and finally I asked here and the solution was posted. I then argued with the svc company who finally sent one of the original guys back who did what I conveyed to him. Guess what? No more issues with that problem.

So that's why I ask here. Kind of like knowing what the problem is before bringing your car to the repair shop/dealer. OK?

[trader4]

All the boiler systems I've seen rely on a thermostat to sense the water temp and keep it within the correct range. So, one place to look would seem to be there. Should be simple to put a tester on it when it's doing what it's doing and find out if that is what is causing it.

You could also find a schematic for the boiler, could be behind access cover on else online. With that you can see what makes it fire, what can prevent it, etc. It comes down to whether you have the necessary skills for DIY. If not, then it probably doesn't matter too much what anyone here can say if you're going to have to call a service guy anyway.

[Stormin Mormon]

My SWAG is dirty cad cell.

Christopher A. Young Learn more about Jesus

.

Because as many, many posts here demonstrate, it's near impossible to find a "good" svc company. It seems that when a good one is found either a big one swallows it up or it/he goes out of business.

That last time I had a problem I had the svc company out three times with three different guys and finally I asked here and the solution was posted. I then argued with the svc company who finally sent one of the original guys back who did what I conveyed to him. Guess what? No more issues with that problem.

So that's why I ask here. Kind of like knowing what the problem is before bringing your car to the repair shop/dealer. OK?

[Stormin Mormon]

Trouble with a safety sensor, possibly a dirty or defective cad cell.

Christopher A. Young Learn more about Jesus

.

This year it has started short cycling. By that I mean that it will start and run for about 15-45 seconds then stop. A few miniutes later it will do that again. It doesn't sound like its failing and stopping, just stopping normally.

I am assuming there is some part or component that may be causing this but because I'm not a furnace guy I thought I would ask here before I dig further. We do have four zones plug a hot water heater connected, each with a separate thermostat.

So, any suggestions as to what it might be?

Thanks

[Ralph Mowery]

It does seem that for a simple system, there are lots of service people that have little idea as how to repair anything. They just change parts and hope to hit on the right one. I had a heatpump that the outside unit was iceing over in the winter. First guy replaced the fan motor . It was iced over two days later, he came backout and said something about a control board. I sent him packing and got another company to replace the system as it was close to 25 years old.

[Pavel314]

ned up" each year by our svc company. This year it has started short cyclin= g. By that I mean that it will start and run for about 15-45 seconds then s= top. A few miniutes later it will do that again. It doesn't sound like its = failing and stopping, just stopping normally. I am assuming there is some p= art or component that may be causing this but because I'm not a furnace guy= I thought I would ask here before I dig further. We do have four zones plu= g a hot water heater connected, each with a separate thermostat. So, any su= ggestions as to what it might be? Thanks

I have a similar system. Over the years, I've had two major problems. One w= as air in the oil line and the other was with the pressure reducing valve w= hich allows water from the supply pipe to flow into the boiler. Not sure if= either of those could be the problem here; your problem sounds more like s= ome electrical sensor giving erroneous feedback and shutting off the burn.

[trader4]

I haven't fooled around with an oil burner in many years. But back then, if the flame sensor tripped it, the thing would require a manual reset to get it to try to restart. Which the OP isn't reporting. Sounds like it restarts again and again on it's own. Will new ones do that? Seems unlikely because of safety issue. You don't want it constantly pumping oil in....

[Mark]

right...to the op determine if the fire actually lights when the burner turns on.

if the fire does not light when the burner turns on for whatever reason, the safety is doing its job and shutting off the burner so that it does not pump the firebox full of oil.

do not bypass the safety.. or you might go boom

Mark