Feed trim, Feed restriction plate or combustion blower... M55 is overheating.

[jumpink]

I've read several posts on the M55 overheating issues since my stove started to trip the high limit switch. I have the original non turbo blower in my stove. I have burned about 30 bags without any issue until yesterday when the limit switch tripped. Stove was set at 3, combustion at 1 and feed trim at 3. I cleaned the stove and reduced the stove to two but it still tripped. The feed restriction plate was installed last year and I fixed the earlier problem with the stove overheating.
I never really played with the feed trim or combustion before. I am going to reduce the feed trim to one and see if this helps. Does the feed trim reduce the quantity of pellets or increase the time between drops? How would I know it is time to replace the blower for the larger output model? Thanks in advance.

Kevin

 

[SmokeyTheBear]

Several things can take care of your problem:

1: Reduce the pellet feed by changing your restrictor plate opening so less of the auger is exposed for loading (less fuel less heat).

2: Increase the combustion air flow (sends more air and heat up the flue, but can reduce the heat exchanger temps enough so the high limit no longer trips)..

3: Install the turbo blower.(increases the air flow in the convection system, thus the exchanger dumps more heat into the room and the high limit is not apt to trip).

4: Really clean your stove as ash in the works retards the exhaust air flow raising the temperature of the heat exchanger and can trip the high limit, fur and crud on the convection blower squirrel cage also reduces the air flow on the convection side of the exchanger raising the temperature maybe high enough to trip the high limit switch,

5: Stop burning high octane pellets made of unobtanium.

Many combinations of the above.

 

[whlago]

My turbo blower is being installed today after over a year of promises First tried the restrcter plate and just didn't care for it.....especially with the need to adjust depending on the quality of pellets you are burning, so I just leave it wide open. I am sick of worrying about babysitting the stove just so it doesn't trip after too long on level 3. My dealer and I have had several discussions on this issue and IMHO the only true fix (to get the most out of the stove) is to use the turbo blower (which...by changing later models of the stove to include the turbo bower the manufacturer defacto agreed that this was the fix). I adjustable auger plate was the equivalent of a bandaid IMO.

To my dealer's credit he agreed with me about a year ago and ordered the turbo blower. The fact that he forgot about it in the warehouse and is just now getting around to installing it is another story.....but that stuff doesn't bother me all that much

 

[bostonfan49]

Jumpink, Hi! I am one of several folks on this board who bought an M55 about 2-3 years ago and had this exact same problem. X amount of stoves were produced with an old style blower that after 1- 2 years gave out ( caused the overheating) this was/is a known issue with Enviro with a new style replacement blower offered under warranty. Some people like myself also got a different style diverter bar and a new, different voltage condenser. The new blower throws a lot more heated air but is not as quiet as the old style. All the newer M55's have a variation of this set-up and your dealer or Sherwood Ind should be able to help you out. Bill

 

[kinsmanstoves]

I am not an Enviro guru and really do not know much about them but I would look at the circulation blower. The only reason I know of that a stove can over heat is by not enough air flow for the amount of pellets being burned.

Eric

 

[bostonfan49]

I am not an Enviro guru and really do not know much about them but I would look at the circulation blower. The only reason I know of that a stove can over heat is by not enough air flow for the amount of pellets being burned.

Eric

...me bad... I should have said, "Convection blower" as Eric correctly pointed out is your blower that needs to be swapped out.....Bill

 

[SmokeyTheBear]

...me bad... I should have said, "Convection blower" as Eric correctly pointed out is your blower that needs to be swapped out.....Bill

Agree you bad.

How ya doing Bill.

We had a good number of folks on here with the M55 or its clones tripping the hi temp switch, the solution so far that actually works is the turbo blower.

Although the combination of 1,2,4,5 can also reduce the issue into nonexistence at the expense of the stoves maximum heat output ability.

It is also possible that your convection blower is cycling by itself due to the heat inside the stove shell when this happens the convection blower actually stops running because its thermal protection circuit protects what is left of the blower at the expense of removing the heat from the heat exchanger. The high limit really isn't going to stay closed in this case.

The manuals for most stoves flat out point to the convection blower as being the likely culprit.

 

[stoveguy13]

Change the blower the old non turbo will work in the steel most of the time but always seems to fail in the cast-iron once it starts the only way to fix it is replace the blower

 

[Wachusett]

Change the blower the old non turbo will work in the steel most of the time but always seems to fail in the cast-iron once it starts the only way to fix it is replace the blower

X2, right on the the money Stoveguy13

 

[jumpink]

Thanks for all the Replies.
Got home last Night

 

[jumpink]

Thanks for all the replies.
Changing the feed trim had a minor effect on the flame reduction. The stove still overheated.
Round two... I have moved the restrictor plate down to the bottom. I decided to clean the blower and found that the squirrel cage is completely disengaged from the end clip that it spins on (see picture). The cage has a good deal of play. Looks like I will have to order a new blower.

 

[stoveguy13]

thats what happens when they go bad.

 

[jumpink]

I pulled the convection fan out and and after further inspection, it looks like the squirrel cage is attached to the motor's yoke by a rubber gasket. The gasket appears to have torn. I suppose the yoke is spinning without the fan or greatly reduced capacity. The replacement fan appears to cost around $260. Is there away to repair the fan? Would epoxy on the gasket work? Budget is a little tight this time of year, would like to find a less expensive alternative.

 

[jumpink]

I removed the fan to get a better view. I've attached a photo of the torn rubber gasket/grommet. It appears that adhesive was only placed on the tip of the gasket/grommet to afix it to the yolk. Now that I have unobstructed access, I am going to try to epoxy the rubber together as well as to the yoke. It's worth a try...

 

[stoveguy13]

How old is the stove should be covered under warranty

 

[jumpink]

How old is the stove should be covered under warranty

Not sure if the stove would still be covered under warranty. It was installed in October 2010

 

[stoveguy13]

two years on the electrical components

 

[JBiBBs5]

Jump, have you resolved the issue with your blower? I have the exact same issue and I thought it was the auger motor because the auger was no longer spinning. After replacing the auger motor it still wouldn't spin so I found the high temp reset solution. That got it spinning again but then I heard the dreadful noise coming from the convection blower. It was making a loud scraping noise so I pressed on the black rubber gasket to see if it would help. The squirrel cage rolled right off the track and ended up looking exactly how yours did in the picture above.

My blower is definitely the older version because I purchased the stove in 09/2011, just before the new blowers were rolling out. Looks like my only option is coughing up $260 for a new blower from mountain view.