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Gaztech
Gaztech, HVAC Technician
Category: HVAC
Satisfied Customers: 488
Experience:  Owner at Gaztech
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I have a Harman P68 pellet stove. The igniter gets hot but

Customer Question

I have a Harman P68 pellet stove. The igniter gets hot but not hot enough to light the pellets. It works fine on manual but will not start on automatic. I say it works fine on manual but that is after starting the pellets with gel starter and a propane torch. I tried a new igniter with no success.If you remove the igniter and hold it close to your hand it does get hot----both the old one and a new one. I took one of the igniters and connected it directly to 117V AC and after a couple of minutes it glows red. In the stove it never approaches that condition.All of the lights seem to sequence properly.
Submitted: 1 year ago.
Category: HVAC
Customer: replied 12 months ago.
I have been waiting more than 24 hours for a response???????
************
Expert:  Gaztech replied 12 months ago.

Welcome to Just Answer, my name is ***** ***** I will do my best to help you with your issue.

If my initial response doesn’t answer your question then let me know and we can continue our conversation.

NOTE: I can only get paid for assisting you if you RATE ANSWER the 5 star rating after you are satisfied with answer.

You will need to measure Voltage supply from your stove to the IGNITOR, your electronic control board is probably not sending the voltage needed.

Customer: replied 12 months ago.
I have already come to the same conclusion. The stove is located about 100 miles from my home at a small ranch I own. I will check it this week.The wiring diagram that comes with the the stove does not show anything that would control the voltage.What would be the purpose for controlling the amount of voltage??
Expert:  Gaztech replied 12 months ago.

There is no reason for that to happen, it would most likely be a defect in the relay that is part of the control board,

Other possible reason would be a restrictive electrical contact through the pressure switch, the light-blue wire to it from the ignitor.

You could measure resistance of pressure switch as you close contact by sucking on the rubber tube that goes to it.

Customer: replied 12 months ago.
Where is the pressure switch and what is its purpose?
Customer: replied 12 months ago.
I have not received a response for my last question.
Expert:  Gaztech replied 12 months ago.

I did respond , Please read carefully

There is no reason for that to happen, it would most likely be a defect in the relay that is part of the control board,

Other possible reason would be a restrictive electrical contact through the pressure switch, the light-blue wire to it from the ignitor.

You could measure resistance of pressure switch as you close contact by sucking on the rubber tube that goes to it.

The pressure switch senses the presence of a functioning exhaust fan, It tells the control board tha fan is working.

Take the time to study your manual, it explains everything, and you need to know these thing in order for you to do maintenance on your unit.

Here is manual...

http://downloads.hearthnhome.com/installmanuals/p68.pdf

Customer: replied 12 months ago.
Okay
Expert:  Gaztech replied 12 months ago.

I am leaving for work, best of luck

Dont forget to Rate my assistance for helping you.

Best regards

Gaztech1

Customer: replied 12 months ago.
I will after making some headway. thanks for the input so far.
Expert:  Gaztech replied 12 months ago.

Chow for now

Expert:  Gaztech replied 11 months ago.

Can you close if we are done?

Customer: replied 11 months ago.
Is it possible for the tube connected to the low pressure switch to get clogged and prevent the switch from operating.
Expert:  Gaztech replied 11 months ago.

Yes absolutely, remove tube and blow into it and check to make sure it's not cracked, it may be dry and brittle, cut off the end if thats the case, and also blow air into the nipple end where tube connects to combustion chamber.

Customer: replied 11 months ago.
The igniter will not operate unless I put a clip lead across the wires connected to the LPS.
Expert:  Gaztech replied 11 months ago.

That is because it thinks the exhaust fan is not running

Customer: replied 11 months ago.
I understand that but with clip lead on and the igniter on the pellets still will not light on auto.
Expert:  Gaztech replied 11 months ago.

Have you done complete maintenance like I mentioned previously?

Customer: replied 11 months ago.
everything has been scrapped and vacuumed.
Customer: replied 11 months ago.
I also bought new pellets. The stove works fine on manual.
Expert:  Gaztech replied 11 months ago.

Clip lead needs to be off before you start process, then when exhaust fan starts.. thats when you put your clip lead within 3 seconds.

Customer: replied 11 months ago.
Okay---I can try that. Could you tell me why?
Expert:  Gaztech replied 11 months ago.

Lets say you shut stove off, fan stops, LPS has to open contact to prove that exhaust fan is not bypassed

Customer: replied 11 months ago.
I also tried a new igniter. I also connected both igniters directly to 117 and both glowed red.
Expert:  Gaztech replied 11 months ago.

So when you re start stove LPS needs to not make contact, the control board says system can start

Customer: replied 11 months ago.
okay
The thermistor does not come into play until after pellets are burning--right????
Customer: replied 11 months ago.
if I use the clip lead properly and assuming the stove is clean, the igniter is good, the combustion fan is running---- what would you do next?
Customer: replied 11 months ago.
By the way--I do not mind rating you so you get paid as long as we can continue working on this problem until I get solved.
Customer: replied 11 months ago.
I guess what puzzles me most is with combustion fan running, the igniter operated, new pellets, and everything closed ---the pellets should start---right??? What else is there??
Expert:  Gaztech replied 11 months ago.

I have left for work and not at my computer until later.

There is just so much time I can spend with your issue

Read your manual thoroughly, part on sequence of operations.

Good luck

Customer: replied 11 months ago.
From your last answer it appears you are finished working with me. The manual by the way is next to no help. I am an engineer and very well versed in electronics and mechanical. I continued to work on the stove and discovered that the wires connected to the igniter were damaged by apparently laying against the stove body close to where they exit the back of the fire box. Both wires had melted insulation and the bare wires were exposed. My sense is this happened when a store maintenance man replaced the igniter less than 16 months after the stove was purchased under warranty. My son said the stove never functioned properly on auto several months after that visit. The guy apparently pulled the wires forward from the back of the stove and then stuffed the wired in the firebox during the installation of the new igniter rather than pulling the exec wiring out the back to prevent them from touching the body of the stove. When I discovered this I pulled the wired out the back of the stove and reconnected them to the igniter outside the stove. When the igniter energized it got much hotter and I am sure it would ignite the pellets now. I plan to repair the wires and reconnect everything but I am sure the stove will now work on auto.
I wish you would have stuck with me on the problem. As a technician early in my career I know every problem is not straightforward and some simply take persistence. Do you really want me to rate you???
Customer: replied 11 months ago.
no one has responded---please close my case. I don't think Gaztech wants my ratting. If so though let me know.