King 5502M exhaust fan (USSC)

[johneh]

cleaning except for the "brass port inside firepot" (it says it could be clogged)

Pull the hose off the vac switch and blow throw it (into the stove)
If air goes through it then it's not plugged. Then again blowing through it could unplug it

 

[SidecarFlip]

Pull the hose off the vac switch and blow through it (into the stove)
If air goes through it then it's not plugged. Then again blowing through it could unplug it

Fixed it for ya.... It don't take much vacuum to activate the switch, the diaphragm is very thin. With mine, when I clean the stove, I use a crevice tool over the inside nipple in the firebox and give it a good sucking.

 

[ARC]

Do I just join the two connectors that connect to the round pressure switch?

Yes that is how you jump the pressure switch, after jumping if exhaust fan runs correctly that means one of two things, bad switch(doubtful as it is new) or you have a vacuum leak that you will have to track down. That could include the exhaust fan gasket, plugged venting or door gasket. Jumping the switch will let you know the problems is vacuum or not.

 

[olivercfc]

Take and run a bead of Red RTV around the perimeter of the flange AND PUT IT ASIDE AND LET IT SET UP FOR A WHILE and then install it. That way when you remove it at a later date (and you will), it will come apart easily.

Got to admit, my first inclination was to install it with the bead of sealant wet to make a nice, real strong bond I'm glad I waited.

 

[olivercfc]

Yes that is how you jump the pressure switch, after jumping if exhaust fan runs correctly that means one of two things, bad switch(doubtful as it is new) or you have a vacuum leak that you will have to track down. That could include the exhaust fan gasket, plugged venting or door gasket. Jumping the switch will let you know the problems is vacuum or not.

The switch is supposedly new but I have doubts that it really is new.
Would it bother you that a new one has a couple of markings like someone making sure they installed it the right way round (even though it's almost impossible to get it backwards.) I guess I could jump it and return the switch if that resolves the problem.

 

[ARC]

Would it bother you that a new one has a couple of markings like someone making sure they installed it the right way round

It would make me wonder if someone returned a faulty switch and then they sold it to you. Are there any numbers on the switch. Should be 80549 and are you attaching hose to the grey port?

 

[olivercfc]

Yep - 80549. Definitely attached to the grey port. I'm wondering the same thing about the return of a faulty switch but I'm naturally paranoid
The jump test should help (getting ready to do that soon)

 

[SidecarFlip]

Probably a return. Nothing to fail inside really. I've never replaced one myself. Clogged hoses and cracked hoses but never a switch.

 

[ARC]

You could try to PM this guy hasn't been on since May 2019 but he is a 5502 guru:

https://www.hearth.com/talk/members/owen1508.32330/

Read threads both state pulsing is normal not sure that is right, also talk about air wash on door:

https://www.hearth.com/talk/threads/useless-pellet-stove-king-5502.150707/post-2037207

https://www.hearth.com/talk/threads...el-5502m-im-having-issues.116001/post-1614960

 

[SidecarFlip]

Got to admit, my first inclination was to install it with the bead of sealant wet to make a nice, real strong bond I'm glad I waited.

You don't want to do that. reason is, it becomes very hard to take it apart to clean it (which you need to do). Letting the RTV vulcanize on the flange and then bolting it in eliminates 90% of the stick but seals just fine. Little hint, I use suitable sized large diameter flat washers under the nuts on the housing studs to distribute the clamping force on the nuts better. Don't need to be really tight, a nut driver gives plenty of hold down torque.

Never touch the draft fan with anything but a soft brush. The heat of operation has made it brittle and it will shatter if hit.

 

[SidecarFlip]

You could try to PM this guy hasn't been on since May 2019 but he is a 5502 guru:

https://www.hearth.com/talk/members/owen1508.32330/

Read threads both state pulsing is normal not sure that is right, also talk about air wash on door:

https://www.hearth.com/talk/threads/useless-pellet-stove-king-5502.150707/post-2037207

https://www.hearth.com/talk/threads...el-5502m-im-having-issues.116001/post-1614960

'Nuther one that bit the dust I suspect. Like Lake Girl moderator, she has been absent for a couple years, must have drowned. Kap and are are about the only 'old timers' left.

 

[olivercfc]

Thanks for the links... I'll take a look.

Todays update is that I jumped the pressure switch and, because I'm lazy, I left the back and side panels off when I started it up. Hopefully, my laziness may have helped.

As it was igniting, I saw some smoke come out of the seal where the vent pipe attaches to the stove. I shut it down and then added more RTV sealant so I'm leaving it for 24 hours to fully cure. Even if that's not the root cause, it can't be good but back in post 8 johneh mentioned a smoke leak as the possible cause.
It was probably in that underneath section because you can't get a caulk gun all the way around and it's hard to see under but I also didn't want to spend too long with my face in smoke (although it's not like it was billowing out but enough to see.)

FWIW, regarding the pressure switch, I disconnected the hose from the brass connector and then removed the brass connector altogether. It's possible removing it dislodged some buildup but it looked pretty clean.

 

[SidecarFlip]

I don't know if this is the proper way to connect the venting to the stove plenum outlet but it works for me and has for years now...

I took a thin kerf cut off wheel in my 4 1/2" angle grinder and lopped off about 3" of the outer galvanized jacket., cut it right where the crimp in the outer jacket is.... That left the inner stainless pipe exposed. Then, I coated the inside of the exposed stainless pipe with Red RTV and slipped it over the exhaust outlet on the stove and added a stout worm clamp. Tightened the clamp tight and let it sit for a day. It's never leaked at all.' ever. I never take it off. When I clean my venting every spring, I leave the section from the stove, through the wall thimble untouched and just vacuum out whatever fly ash is in there. Do the same on the inside after removing the draft fan.

Going on 15 years like that actually.

 

[olivercfc]

Just wanted to give an update to say I have no idea what is going on.
I wasn't happy with the seal that the RTV gasket made so ordered a paper/cloth/whatever-it-is replacement, then on the next test saw smoke coming out from near where the vent pipe entered the stove. Upon closer inspection it was coming from a seam in the pipe where it can rotate (the stove is in the corner so turns 45 degrees to vent out through the wall.)

Once I got it all sealed, I tried the diagnostics again and had the same results as before. Same pulsing exhaust fan with the 'draft fan' light flashing.

I thought I'd run it anyway to see how long it lasted and it actually stayed on for hours. At first, the 'draft fan' light continued to flash but after a while it stopped flashing so there's no visible sign of a problem. No idea when that flashing stopped as I wasn't watching it that closely. To confirm, the vacuum switch is no longer jumped and on shutdown, it does the proper thing where the fan comes on full for about 20 minutes or so and pellets continue to drop (I think I read that's to avoid burnback)

I ran it again a couple of nights later and it was good again so I'm just hoping it gets me through this season and then I might look for a replacement.

Thanks all for your help and advice along the way

 

[gman88]

Hello,
We have a 5502M coming on for it's fourth year of operation.

We put it through the self-test and the exhaust fan is not working properly. It's supposed to turn on full and then reduce to a level just above the minimum pressure switch setting according to the manual.

Instead of turning on full, it tries to spin up (we have the panel off on the right-hand side as you look so I can see it moving a bit) and gets to what I guess would be about 1/10th of what it should be before spinning down and trying again. This repeats every two seconds or so until I move on to the next test.

Any idea what this could be? I took the fan off and cleaned out the ash/soot from inside the housing and the fan spins freely when pushed by hand if that makes a difference.

I'm by no means an electrical expert but I do have a multimeter so can I remove the fan and test whether the connectors are receiving the right power from the control board? Or is this likely to be something else entirely?

Thanks for reading

I know this is old but, after having an unrelated problem with our stove and doing some repairs, I ran our 5502M through the self-test and perceived the same "problem". I did some searching and found this post. I joined the forum just to respond (I'll probably be around - these things are fussy). Somewhere in our house we have a manual. I couldn't find it and the only thing I could find, online (fast), was for a 5500M. They look identical (the 5500 and the 5502) and I presumed the self-test indications were identical. I just got off the phone with Kelly, a tech person at the factory. She seemed very knowledgeable and said, "Oh, THAT MODEL (the 5502m) does that - it ramps just a little and cycles about every two seconds......". She said that I should run the test, and, on that first test (for the exhaust fan) walk around and open the glass door on the front. She said the fan should, then, come on full. Great. The weekend just passed and I ordered on exhaust fan on Ebay, for 75 bucks, last night. I did what she told me to do and, of course, it worked just as she'd described. If you have a 5502M and it does what you originally described in your question, that's what it's supposed to do.

 

[ARC]

Somewhere in our house we have a manual. I couldn't find it and the only thing I could find, online (fast), was for a 5500M.

5502M manual