Harman Boiler Is Now Cooperating! (General Harman Control Board Operations)

[SmokeEater]

It's the weekend and my dealer is closed til Monday! Have been working alone to DIY my conversion from cordwood hot air to hot water and today was to be the first fire for my PB 105, but, for some reason I can't figure, it won't start. First, when powered up and according to the manual, the control board was to start the combustion fan on high, auger, and overheat circuit, and then all status LEDs were to go off except for the combustion fan's LED and the fan, which was to change speed to low after a minute on high. This was when the feed adjuster knob was turned to TEST. Nothing happened except the status LED was blinking in 3s indicating that the ESP probe has gone out of range. Checking with the dealer suggested I check for loose or broken wiring on the control board. Sure nuf, one of the leads from the ESP sensor was broken at the connector, Got a new connector and wires, wired it up and powered up, still nothing! That's where I'm at for the rest of the weekend. All I got was that the power, status, and overheat LEDs came on and then, after about a minute, the overheat LED went off. No auger movement and no combustion fan. I know a lot of you have Harman stoves, furnaces, and boilers out there. Maybe you could help me discover my problems with this one before the weekend ends so I won't be as discouraged.

 

[DexterDay]

Bunch of Harman Guru's on here. Hopefully someone will be along to help you out?

Would love to see some pics?? Always love to see different set-ups.

 

[SmokeEater]

This is one of the latest pics taken about a week ago. Had some leaks to repair (still have a few small ones). There's an oil backup kinda hidden in behind the buffer tank to the left. Both boilers are independent of one another or both are "cold start". The oil will (should) only come on when the tank temp reaches a preset low point (to be determined).

 

[wil lanfear]

Check to see that the igniter switch on the controller is in the auto position. The auger will not feed pellets on startup unless the switch is in auto.

 

[SmokeEater]

Check to see that the igniter switch on the controller is in the auto position. The auger will not feed pellets on startup unless the switch is in auto.

Wil, thanks for the advice. I tried to start it, both, in the manual and auto position and I get the same.

 

[Ejectr]

I know this is a stupid sounding suggestion, but check to see if the fan under the plastic guard cover on the outside of the combustion blower turns freely. When I installed my PF100, the fan was caught on the plastic cage cover and wouldn't allow the combustion fan to turn which didn't give any negative pressure, which didn't allow the auger to feed pellets. The installer took off the plastic cage guard and away she went.

 

[wil lanfear]

If the combustion blower won't run, the auger won't run. Remove the front cover and check to see if the combustion blower is plugged in. If it is, unplug it, with the boiler powered on, confirm with a voltmeter that you have power going to this blower. If you have power at the plug, turn power off to the boiler, remove the combustion blower to see if it turns freely or it's not turning at all. The combustion blower has to run prior to the auger running.

 

[SmokeEater]

I know this is a stupid sounding suggestion, but check to see if the fan under the plastic guard cover on the outside of the combustion blower turns freely. When I installed my PF100, the fan was caught on the plastic cage cover and wouldn't allow the combustion fan to turn which didn't give any negative pressure, which didn't allow the auger to feed pellets. The installer took off the plastic cage guard and away she went.

Ejectr, I'll try. Sometimes the least obvious things will work out.

 

[SmokeEater]

If the combustion blower won't run, the auger won't run. Remove the front cover and check to see if the combustion blower is plugged in. If it is, unplug it, with the boiler powered on, confirm with a voltmeter that you have power going to this blower. If you have power at the plug, turn power off to the boiler, remove the combustion blower to see if it turns freely or it's not turning at all. The combustion blower has to run prior to the auger running.

Wil, I'm sure leaning that experience is the best teacher. I don't know why I didn't try the voltage check before, but it makes sense that if the combustion blower LED is lit, then there should be voltage at the fan. If not, then that's another solution.

 

[wil lanfear]

Also, make sure that the low temp set dial isn't in the off position, set it at 140* for now.

 

[SmokeEater]

To Ejectr and Wil

The Hearth Forum's GURUs were both correct!! Before yelping for help, I had taken the fan motor assembly off and spun the blower fan and all seems free with no frictional drag. But as Wil suggested, I checked the voltage at the fan and had 113v there. Then, as Ejectr suggested, I removed the plastic cover over the combustion blower's cooling fan and hit the power and
VOILA! On came the blower and auger. I rechecked all, put in a bag of pellets, reset the controls and she started right up and in twenty mins she raised the temp of the boiler water from 55* to 130*. I let it climb to 175 then 185 and shut it down because my aquastat had not started the boiler pump and should have. I'll play with that tomorrow. Thanks so much Wil and Ejectr for the wise help.

 

[Ejectr]

Great news! You're more than welcome. If it hadn't happened to me, I probably wouldn't have been able to help you.

It seems that combustion external fan cage is just at the right height where a furniture moving dolley can put pressure on it and bend it enough to jam that fan. Once the fan gets jammed, the combustion motor won't turn. Wish I had remembered that last night and you would have been running sooner.

 

[Ejectr]

If it is the same as my HS Tharm wood/oil boiler I once had, the aquastat setting is what controls the burner or in your case, the fire. The thermostat calling for heat is what should turn on your circulator. That's usually connected through a relay box that picks up the relay and the relay contacts supply 120v AC to the circulator motor. There are also some aquastats and relay control boxes that will not supply 120v AC to the circulator circuits unless the water temp has reached 140 degrees.

May be different on the pellet boiler, but I don't think so.

 

[DexterDay]

Nice... Glad your up and running!!

 

[wil lanfear]

Good to see that it's up and running for you, its a learning process that I'm sure you will enjoy as I am.