Harman HydroFlex 60 Pellet Boiler - New Install with Ignition (Feed) Problems

[Tim M]

Hello,
I had a HF60 installed a few months back. It is plumbed into our existing oil boiler. Seems like problematic from the start.

I just cleaned the pellet boiler and turned it back on. Temp min @ 170, max @ 185, feed @ 6, ignite @ auto. Feed motor ran continuous for 16-1/2 minutes. I was watching it closely - it never stopped or shut off even momentarily. Then it blinked a few times - shaking the pellets I guess. By this time the pellets were long since been dumping. They started dumping at the 7 or 8 minute mark. Obviously way too many pellets. When the feed motor finally stopped after 16-1/2 minutes then it started to produce smoke. Lots of smoke. The burn chamber became totally obscured - couldn't see the pellets anymore of the burn pot - totally smoke filled. Now the smoke is in the basement and pretty smelly - actually you can smell the smoke in the entire house including ground floor. At the 18 minute mark, the feed motor turns back on. At 18-1/2 minutes, it finally ignites with a POP. There had been a HISS from the back of the unit the entire time. The HISS turns off now. The ignite lamp turns off. The flame is a lazy not good flame. There are too many pellets in the pot. The pellets are still dumping although at least they are starting to burn now. Feed motor keeps running and pushing pellets much faster then they are being burned so still dumping pellets. Feed motor is NOT cycling at this point - just running all out. Watched it for at least 3+ minutes and it ran solid with no cycle. At the 24-1/2 minute mark, the feed motor stops and cycles a few times on a 15 second cycle. It is not until maybe 30 minutes from starting that there is finally a good flame and normal amount of pellets with feed motor cycling properly.

At other times, I have seen this ignite properly in 3 or 4 minutes. The installer did swap the electronics board which did not seem to change anything. Seems like the issue is the feed motor doesn't shut off. The couple times I watched when the feed motor DID shut off - it ignited with no problem. At least twice I watched with a watch that it took about 20 minutes to ignite and the problem seemed to be the feed motor never stopping. Other times not watching but smelling the smoke upstairs - I assume same thing happened. When it ignites in 3 or 4 minutes there is minimal smoke in the burn chamber - almost none and it is not able to be smelled upstairs. So I assume that if I smell the smoke (strong) on startup that it was a bad startup.

At this point, I mostly run in manual mode so it doesn't shut off and have to re-ignite. First - it is cold outside (13 degrees F right now) so makes sense to just keep the pellet boiler running as we need the heat. Second the auto ignite is sporadically working/not working so I don't want to have it doing poor ignition. But that means I don't have a good feel for how often it would ignite proper and how often it would ignite improperly. Come springtime - I had certainly intended on putting it into AUTO mode and have it shut down and re-ignite as needed.

Burning Turman Hardwood Pellets. Length of pellets is around 1-1/4 inches. Seems fairly consistent length with broken pellets down to maybe 1/2 inch?. Don't see any pellets at 2+ inches. However I would not think the type of pellet (hardwood or softwood) would have any impact on how long the feed motor runs or doesn't run.

Dip switches have 5 and 8 on (up). Installer set them that way - I have not changed the switches. Burning outside air. The connector for outside air temperature "set back" is NOT installed. Exhaust direct vent maybe five feet straight run through the wall. Screen on the end of the vent was removed as it seemed to clog up fast.

Thoughts?

Thanks.
Tim.

 

[VT_Bubba]

Hello Tim,

It sounds like you resolved your other installation issues and you are now able to clean your HF60 boiler properly.

I'm on my 3rd HF60 heating season and have never seen a single unburnt pellet in my HF60 ash pan. However, I can't imagine running my HF60 with your settings (170-185 feed rate= 6), with any pellet, under any conditions. This is like starting your car and putting the peddle to the floor (basically, Max Boiler settings). These little HF60 boilers just can't take that kind of hard use. IMHO the HF60 is really a 30-40K BTU Boiler. For my installation I can get by with that. We love this little boiler. I wish Harman would have made a HF90 or HF120 boiler (90-120 KBTU in this design).

I run my HF60 at 165-180, feed rate= 3 to 4 in auto mode. My HF60 may fire 10-20 times a day on some days ! I scrape my burn-pot once or twice a day, vacuum the exchanger and fan about every 2-4wks, depending on use. They do run better when they are kept clean. For my installation the shoulder months are the best, because the boiler is not used hard, stays cleaner longer, and the auto ignition enables very little pellet use. I have left my house once for 4-days (3-nights) in below-zero weather, and once for 3-days (2-nights) in 10-20F weather, and the HF60 ran flawlessly unattended with almost no pellets left in the hopper when I got home. Note, in both of those cases I did leave the house with my woodstove also fully loaded, and I do have fully automatic oil backup if the HF60 would ever fail to stay hot.

The high BTU hardwood pellets (Greene Team, Cubex) seem to have smoker ignitions and more crust in the Burn Pot, potentially blocking the air holes . The Softwood pellets (LG) seem to have faster, cleaner ignitions, but more ash, and less BTU's. I personally like to mix GT and LG. This seems to give me faster, cleaner ignitions, with reasonable BTU's and minimal crust in the burn pot. This year I have been mixing Maines Choice, GT, and LG. Overall, Greene Team is still my favorite pellet. I have never tried the Turman Hardwood Pellets.

Good Luck on your HF60 problems and please keep us informed with what you learn !
VT_Bubba

 

[Tim M]

VT_Bubba,
My understanding is that the feed rate is not relevant for ignition and only comes into play while the boiler is running. So my question now is what could be causing the improper ignition?
Thanks,
Tim.

 

[VT_Bubba]

Tim,

Your right in principle, however ,the feed rate can be indirectly related to ignition problems. Your boiler is not igniting, but it keeps feeding pellets at the highest rate. So, when this happens you end-up with even more pellets in the burn pot, making an even bigger mess. Your high feed rate is also causing your boiler to get dirty faster (very rich burn mixture ==> the same amount of air with the most more fuel), which also makes ignition harder. I'm not saying your problems are 100% caused by feed rate. I am saying FeedRate=6 is not a sustainable setting for your HF60 boiler (says that right in the manual) and is sure not helping your ignition problems either.

Your describing the same type of problems that many PB105 users have had. It is my understanding that with the newer pressure ignition PB105's (same ignition as the HF60) most of these problems have been related to draft issues at the burn pot :
- Problems with the Air-In path (Blockage, or Negative Draft in the house)
- Problems with Exhaust Out (Exhaust Issues, Leaks, Dirty Boilers, fans, and Pipes).
- Bad PB105 Hopper Door Seal (recently found on a buddies PB105 here in VT , by a Harman Factory Tech).

I would encourage you to get with your Harman Dealer to have them resolve this issue, or make them get a factory tech to your house to make the draft measurements in both the firebox and right at the burn-pot itself. That's how they found my buddies PB105 hopper door seal problem.

I'm hoping some other HF60 owners will comment with their experiences, advice, and problems. Your the only HF60 Owner that has commented with this type of problem.

Once again, good luck and please continue to share your learning with the forum.

VT_Bubba

 

[wil lanfear]

Tim,
Dip switches 1,2 and 3 control the amount of pellets fed into the burnpot on start up only so..... if you have the feed rate set at 6, it could be possible for the auger to feed excessive pellets into the burnpot, overfilling the burnpot. Where are the dip switch settings on your boiler? On my PB-105, the switch settings are #1 0ff, #2 off and #3 on using a feed rate set to 4.5. ( off is when the switch is down) These settings provide for quick ignition without overfilling the burnpot on startup, maybe something you might try.

 

[VT_Bubba]

Tim,

Per Wil's good advice above, I found the Harman Documention they provided with replacement control boards last year 2012 (doc updated Dec 15,2010) :

The standard Harman HF60 settings should have Only Sw5 and Sw8 in the ON position, all other switches OFF. These two switches (SW5 and SW8) are setup based on the ESP probe type and Temp used on the HF60.

However,SW1,SW2, and SW3 can be used to alter the amount of pellets loaded in to the burn pot on ignition start-up, as follows :

SW1,SW2,SW3
------------------------
OFF,OFF,OFF - Use Pgm Default Pellet Load Times (Note: This is the recommended setting for the HF60)
OFF,OFF,ON - Use Pgm -21 sec
OFF,ON ,OFF - Use Pgm -43 sec
OFF,ON ,ON - Use Pgm -64 sec
ON ,OFF,OFF - Use Pgm +21 sec
ON ,OFF,ON - Use Pgm +43 sec
ON ,ON ,OFF - Use Pgm +64 sec
ON ,ON ,ON - Use Pgm +85 sec

I have never looked at my factory HF60 settings, because I have never had any problems. I have noticed that having less pellets in the burn-pot on ignition makes for a faster and cleaner ignition (the more pellets on startup seems to cause slower and smokier ignition), this is true for both the HF60 and the PB105. Both of the non-preasure ignition PB105's that I know of have changed these switches (SW1,SW2,SW3) similar to Wil's recomendation above to help eliminate smokey startups and pellets in the ash pan.

I encourage you to make sure your boiler and exhaust pipes are clean first, then try some of the settings above to load pellets for less time during the ignition. As stated above, I also highly encourgage a slower FeedRate (4 would be a good start).

As always, I hope you will share what you learn with the forum. Good Luck !

VT_Bubba