Fixing my PB105

[clancey]

That is neat and I think in the old days they did coal or something like that for my old house had just a door way and a long drop to the basement and I think there was the steps and a ramp of some kind that went over it but I am not sure but found a chunk of coal in the basement area..(1926 single bedroom 491 square feet--23x23 house at that time..Neat idea out of the scrap I think..old mrs clancey

 

[johneh]

who get the bottom of the stairs to ply catch

 

[White00s10]

The Girlfriend offered to catch and stack as they come down the slide lol.

 

[johneh]

So you will be looking for a new Girlfriend

 

[tlc1976]

That is neat and I think in the old days they did coal or something like that for my old house had just a door way and a long drop to the basement and I think there was the steps and a ramp of some kind that went over it but I am not sure but found a chunk of coal in the basement area..(1926 single bedroom 491 square feet--23x23 house at that time..Neat idea out of the scrap I think..old mrs clancey

People I knew with a wood furnace in the basement would remove a basement window and chuck the wood down there. Coal you could have a smaller dedicated chute, but you could always just pop out a window too. My buddy’s folks got an old coal furnace converted to gas.

 

[tlc1976]

The Girlfriend offered to catch and stack as they come down the slide lol.

First I read it as she would catch and stack as long as she could go down the slide. That would have been my ex wife.

 

[White00s10]

 

[White00s10]

Well, took about 4 hours total to get all 4 tons in the basement. I was planning on only doing 3 initially, but decided to push and get one more pallet just in case. Last thing I wanted to do was do this again in winter! And the chute worked great!

 

[Washed-Up]

The GF pulled it off

 

[White00s10]

Well, buddy whose an HVAC tech came over and helped me out this weekend with running the plumbing and wiring up the relay to control the circ pump with the thermostat.

First fire up went without a hitch! Can't wait too run the boiler full time this winter!

 

[Mr._Graybeard]

Looks good. Remember to set that minimum temperature high, especially during the shoulder season when the boiler is likely to sit idle at times. It may short-cycle during the day, but you want to keep the water temp above 140 as much as possible to limit condensation and creosote. In fact, it may be a good thing to short-cycle a bit if you still have some residual goo in the unit.
I actually run my oil boiler until the highs are down into the 40s.

 

[White00s10]

So, i did a full startup today to see how its gonna work.

Is this how its supposed to normally operate?

Cold startup.

Turn unit on, pellets feed ignitor lights.

Pellets ignite

Unit feeds and burns till max temp is reached ( I had it set at 185. It actually overshot and stopped at 200).

Unit shuts down. Status light goes off, it stops feeding, but combustion blower continues to run.

Combustion blower shuts down

Unit maintains internal heat till minimum temp is reached.

Wash rinse repeat.

This sound correct?

 

[Mr._Graybeard]

Exactly correct. The combustion fan runs until the ESP determines that flue temp has dropped sufficiently to guarantee that fuel in the firepot has burned out.
Former Farmer has a PB105 with the finned igniter, IIRC, but I would set it to start the igniton process as soon as the temp starts to drop. If it takes 5 or 6 minutes to light, your jacket temp could be down around 140 degrees quickly if you have a lot of radiators.

 

[Mr._Graybeard]

Adding: I also set it at about 185 max and get similar results, with the temp gauge reading about 200. I recall some boiler owners setting it a little higher, figuring water pressure would keep it from boiling, but I was definitely getting some bubbles when I tried setting it higher. The hottest point in the jacket is not where the gauge is located.

Have you set up a dump zone? It's nice to have if you run the boiler igntion on manual, but my boiler has never overheated on auto in the nine seasons I've used it.

 

[Former Farmer]

Have you set up a dump zone? It's nice to have if you run the boiler igntion on manual, but my boiler has never overheated on auto in the nine seasons I've used it.

I have had the dump zone used several times. It only happened when I run the boiler in manual mode and we would get a couple of very nice days in March that would warm up the house. It never happened when I run in auto. I used manual for a while because of all of the issues with the burn pots.

I won't be using the PB105 much this year again. Propane is cheaper than wood pellets for now. I had my 2 propane tanks filled this summer for $1.24 per gallon. I have enough propane to last me an entire year. Cost of propane at $1.24 is $14.33 per MBtu versus cost of pellets at $240 per ton is $18.46 per MBtu.

 

[White00s10]

No dump zone plumbed in right now. I plan on using auto, so hopefully, it shouldn't be an issue.

Few things. I noticed my burnpot developed a bump over the ignitior. I read in various threads that this is comon with the oem burnpots, so i bought a new heavy gauge updated design stainless burnpot.

Also I noticed if i go out from a total cold start, the boiler will run till it gets up to about 120° before it sits there and idles back the fire. If i turn it to test and manually get it to feed a bunch and ramp up the flame, itll usually catch and start running in auto once the unit gets above the min temp. Im wondering if the aqua temp probe is faulty or the esp is suspect. Either way both new ones are in order also.

Does anybody have a pic of the spring that holds the temp probe in the top of the aquastat well? Mine seems to be missing and my be giving the board a false reading.

 

[Mr._Graybeard]

No dump zone plumbed in right now. I plan on using auto, so hopefully, it shouldn't be an issue.

Few things. I noticed my burnpot developed a bump over the ignitior. I read in various threads that this is comon with the oem burnpots, so i bought a new heavy gauge updated design stainless burnpot.

Also I noticed if i go out from a total cold start, the boiler will run till it gets up to about 120° before it sits there and idles back the fire. If i turn it to test and manually get it to feed a bunch and ramp up the flame, itll usually catch and start running in auto once the unit gets above the min temp. Im wondering if the aqua temp probe is faulty or the esp is suspect. Either way both new ones are in order also.

Does anybody have a pic of the spring that holds the temp probe in the top of the aquastat well? Mine seems to be missing and my be giving the board a false reading.

The temp sensor in the water jacket can be tricky. Other people have had trouble with it. I think I recall one person using the spring from a retractible ball-point pen to space the sensor properly in the well. If it shuts the boiler down too quickly I'd suspect the sensor is too close to the water jacket. That said, I've never had the problem myself.

 

[White00s10]

The temp sensor in the water jacket can be tricky. Other people have had trouble with it. I think I recall one person using the spring from a retractible ball-point pen to space the sensor properly in the well. If it shuts the boiler down too quickly I'd suspect the sensor is too close to the water jacket. That said, I've never had the problem myself.

Well, I put the new aquastat probe in, wired it up, grabbed an old pen, pulled the spring out, and dropped it in the well before I put the probe in the unit.

Fired it up, and set my max at 185 (highest my controller will go) and the min for 150.

Stove fire up, burned to 190 degrees without a problem, and shut down.

Think I'm ready for winter. Thanks again for all your help! ! !

 

[Mr._Graybeard]

Well, I put the new aquastat probe in, wired it up, grabbed an old pen, pulled the spring out, and dropped it in the well before I put the probe in the unit.

Fired it up, and set my max at 185 (highest my controller will go) and the min for 150.

Stove fire up, burned to 190 degrees without a problem, and shut down.

Think I'm ready for winter. Thanks again for all your help! ! !

I'm glad that worked for you. I would probably set the min temp somewhat higher. Maybe Former Farmer can weigh in with experience setting the min temp on a boiler with the finned igniter.

Oh, and the general consensus has been to set the pellet feed rate at 4.

 

[Former Farmer]

I run my boiler at 145 min and 165 max. I have a completely different setup than most people though. It supplies heat for domestic hot water, forced air heat, and in-floor heat.

It is hard to take a guess as what to set the minimum temp at. It will depend upon the flow coming back from the baseboards as well as the temperature of the return.

If I remember right, the PB105 holds 30 gallons of water. If your circulating pump pumps 2 GPM and it takes 5 minutes for startup, you just changed out 1/3 of the water in the PB105. If you have your min set at 150, and your return temp is 90, you have a difference of 60. So you would drop your temperature in the boiler 20 before you start producing heat.

I would agree with Graybeard, your min may be a little low. You will have to monitor it and figure out what works best for your setup.

 

[Mr._Graybeard]

Thanks, FF. The reason I dwell on the minimum is because condensation can form when the temp in the burn chamber drops below 140f. Condensation is bad for any type of boiler, be it wood, oil or gas. These pellet burners take a little time to start up, and a hydronic system can feed in a lot of cooler water once the circ pump starts. I suspect your radiant system sees a lot of water circulation, so the water moving into the boiler hasn't cooled off that much.

I have cast iron and slant-fin baseboards, and the slant fins in particular shed their heat quickly. So that's my experience, and why I recommend the higher minimum temp.

I don't recall White00 telling us how his home is heated, so my advice could be way off. A heat exchanger in a hot-air duct is basically just one big radiator, so with that kind of load he may not have to worry so much.

 

[Former Farmer]

I suspect your radiant system sees a lot of water circulation, so the water moving into the boiler hasn't cooled off that much.

My system is a closed system that I draw the heat off of the PB105 via a water to water plate exchanger. The circulating pump on the PB105 runs all of the time the unit is powered up. I have the circulating pump drawing heat from the plate exchanger turn on only if the water temp in the PB105 is above 140. That is how I control the condensation issue.

The system that the PB105 is tied into can only handle temperatures up to 170 per manufacturers specs. That is why my max temp is set at 165.

 

[Mr._Graybeard]

Interesting. I would love to have radiant heating ... but our old farmhouse would require some major renovations to make that work. When we bought the place it had steam heat! It was nostalgic, but not very efficient.

 

[White00s10]

The house has slant fin baseboard heat. I had my HVAC guy put in a thermal loop before the circulator pump to draw hot water off the supply side and mix it with the return before its pumped back into the boiler, Im still dialing it in, but so far temps haven't dropped below 140 degrees yet.

something else ive noticed,

if I try to do a cold startup (totally cold boiler) the stove feeds pellets and ignites just fine, but once it hits 130ish, it just stops feeding and lets the flame die out. I have to turn the min dial to "off" than turn my min temp back to the low set point (150 degrees) and let it go thru the automatic startup again. Than once it gets to the minimum set point, it continues feeding till it hits the max, and shuts down.

once that point is reached, the boiler works as it should, maintaining water jacket temp between the min and the max.


Dip switches set for Auto startup, +43 seconds for feed amount (1,2,3 is on,off,on)
Brand new Aqua temp probe.
OAK
esp was cleaned with steel wool at the start of the install.

any ideas why the boiler struggles with cold starts? or is this normal?

 

[Mr._Graybeard]

I think the placement of that aqua sensor needs to be adjusted. Again, I've never had that problem, but I think that was the culprit when other PB105 owners reported a premature shutdown. I think you might have to increase distance between the sensor and the water jacket.

It might be worth a call to Harman to see if they can offer some advice. They're not known for customer support, but never say never. Earth Sense is my Harman dealer, and they've been helpful to me. Maybe try them as well. And search the forum archives!