Whitfield Advantage IIt room blower speeds up/slows down with auger feed

[Shastafarian]

Hi,
My Whitifield stove, maybe 15 years old or so, has something wrong with the room air blower. When the stove is first started, and when it is cooling off, and also occasionally while running, the room air blower will speed up while the auger feed is running, then slow down again. For example, while the auger is set on 2, the fan will cycle from slow to fast and back again every 7 seconds or so.

Any advice on how to fix this?

Thanks!

 

[Stovensen]

Hello Shastafarian, Welcome to the forum. My best suggestion is a 'tired' low limit switch... the contact points inside this switch are worn, resulting in an unstable neutral to the entire stove. See diagram below. It's easy to check the low limit switch for proper function. Two methods: One is to bypass the switch with a jumper wire and see if the stove stabilizes. Another method is to measure the voltage drop over the terminals of the switch with a voltmeter while it is running... on a healthy low limit switch there should be no voltage drop. If there is a voltage drop cycling up and down together with the blowerspeed, then you know for sure that the switch is faulty.


Edit: The low limit switch is bypassed by a relay for the first 30 minutes at start up in order to allow the stove to warm up, so if the blowers are stable in this period, this could also indicate a faulty low limit switch.

 

[Shastafarian]

Great, I'll try it out! Thanks!

 

[Shastafarian]

Jumpering the switch had no effect...any other ideas?

 

[Stovensen]

The molex plug is the next suspect then. It should be similar the one on my stove. See photo. Note: My plug is coated with anticorrosion contact spray.

Pull it off and examine the metal terminals for corrosion or if the terminals are bent out of proper contactmaking shape. You may have to use lamp and a magnifying glass for this inspection. Corrosion could simply be ground off by pulling the molex plug in and out a number of times. If you have some contact cleaning spray ( available in electronics shops ) that would be the best method, though.
All the other plugs in the wiring harness should also be inspected, cleaned etc.

If this doesn't help... well, then something must be faulty on the control board. On the control board of our Whitfield stoves there are test points for the output signal of both blowers and auger motor. These test points are hidden under the four nylon plugs at the bottom of the control panel.


If you want to diagnose the output voltage for your convection blower, you could use this Youtube clip as a reference of how a healthy signal should look like. I made this test some time ago, as I was having a rather annoying whining sound from the blower at setting 3/5.

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Good luck and take care.

Edit, the whining sound issue is solved by now... on triac controls it is impossible to avoid these harmonics from turning acoustic in the motors, but luckily the control board has a built in remedy for this: A small trimpot to fine tune the speed of the convectionblower away from the ringing/resonating point. This trimpot, however, is well hidden on the back side of the control panel. See photo. Your Advantage IIT probably has this trimpot too. Now, if this trimpot is dirty inside ( most likely after 15+ years ), a good cleaning of its carbon trace and wiper could be all that is needed to stabilize your conv. blower. Just a thought.

 

[Shastafarian]

Hi, I cleaned all of the contacts and pots. This made no difference. The last couple of mornings, with outside temps in the single digits, the exhaust fan would not start - I had to go outside, open up the cover to access the back of the stove, and knock on the motor with a hammer to get it going!

I'm considering replacing the stove - aside from the current issues, there is just too much noise and we'd like something quieter.

 

[Shastafarian]

I am going to put in a new control board....$400 is a lot but still way less time and effort and money than getting a new stove!

The exhaust fan has difficulty starting since I oiled it. I realize I should probably not have done that. I used 20 wt - which is probably too heavy. I will try to get some lighter oil in there, hopefully it will flush out the bearings and the fan will operate normally.

 

[Stovensen]

You may find this service manual useful. It's the original Advantage II-T/Advantage III svc manual:

(broken link removed)

$400,- for a new control board is a lot of money. Please read this thread where forum member susb8383 had her control board repaired with great succes by David in Canada:
https://www.hearth.com/talk/threads/whitfield-advantage-plus-do-i-need-a-new-fan.102726/

Good luck and keep us posted

 

[Shastafarian]

Thanks for the service manual. Yeah, $400 is a lot, but I didn't want to go for several weeks burning propane for heat while it was out for repair - that could have cost close to $400! I got the new board today from Rainbow Hearth in Redding, CA and hooked it up - same exact connection, but it's an upgraded board (old one had rotary controls, new has buttons). The oscillation is totally gone, and the stove is much quieter. I will see about getting the old board repaired - then it will either be my backup or will be for sale.

 

[Pellet-King]

You might look into a new combustion blower, it's most likely on the way out, I replaced mine last year and having to get it moving several times, also replaced the auger motor and the new one is sooo quiet.
Your stove is older than 15 yr's as mine was bought around '98 or '99 and had the newer board.

 

[Shastafarian]

It was manufactured in 1990, serial # 22,844. I'm looking at this combustion motor:
(broken link removed to http://www.electricmotorsandpumps.com/fasco-a082-motor-and-blower.html)

 

[Stovensen]

Your stove is older than 15 yr's as mine was bought around '98 or '99 and had the newer board.

Mine is from '98 and also has the newer board with touchpads. Luckily for the OP the new board was plug and play with the existing plugs. Congratulations with a working stove.
Also congratulations to forum member Pellet-King... your message counter has hit exactly 1000