I have a BURNHAM oil burner (model 3WRH) that has recently been needing to be reset about 2-3 times every week. The unit had just gotten a block replaced. The reset entails pressing a red button on a HONEYWELL (R4184 D 1027) ignition reset switch. The burner always comes up after reset.

Up until recently this switch was rarely used, maybe twice in 7 years. Now, it happens almost every few days. More than likely something to do with the block being replaced?

Your thoughts?

 

I don't know what you mean by the block. The most common reasons for intermittent lockout are weak ignition and dirty flame sensor. If it starts up every time without and rumbling it may also be a defective burner motor. You can check the flame sensor with an ohm meter or by looking at the glass to see if it is smoke covered. The transformer can be checked with an insulated screwdriver by drawing an arc across the terminals. You should get a 3/4" blue spark if it is good. If you need details on any of the checkout procedures, reply to this post and I can elaborate.

Ken

 

Ken,

By 'block' I meant the actual boiler inside the heater. It was cracked and needed to be replaced, so my contractor came and replaced it and in doing so practically took apart the entire boiler.

The flame sensor visually (not dirty) appears to be ok. Using an ohmeter I was able to get not quite zero when I shined a light on the sensor. Should I get zero? About the transformer, however, I'm not sure between what 2 points I need to short and where I would look for an arc. Do you mean between the 2 terminals leading to the light sensor?

Appreciate your help.

John

 

I think the flame sensor should have a resistance of more than 3000 ohms when dark and less than 300 when lit by the flame. Yours sounds OK. Remember though that you read it when shining a light into it. If the flame is set with way too much air, the flame will be dim and may cause a problem then. Hopefully your repair tech set the burner up with test instruments after re-installing the burner. To check the transformer, turn off power, lay it back so you are looking at the 2 spirng terminals. Pull out the flame sensor and turn on power while starting an arc across the terminals with a good insulated screwdriver. Pull the screwdriver away from one terminal while letting it rest on the other one. You should get a 3/4" spark before it breaks. You will only have about 45 seconds to test before the control locks out. When you close ii up there will be some excess oil in the combustion chamber so don't be alarmed if it rumbles a little on the next start. If it checks out good, you might consider checking the resistance of the flame sensor while the burner is running and see what it reads when illuminated by the flame.

Ken