Whitfield Adv ll-T Lazy burn

[SmokeyTheBear]

Well, I hooked the pressure switch back up and it ran great for around and hour before the lazy burn came back. I looked in the back during the cool down process and found that the combustion fan wasn't running. Later when stove had cooled down more it came back on. Once it was completely cooled down I turned the fans back on and everything was good. Obviously something is causing the fan to slow/shut down once the stove gets hot. What's the best place to start for chasing electrical?

OK the thermal on the combustion blower is being tripped, please tell us all about your vent system.

Or the bearings are old and worn. My old Englander I got last year was like this. I oiled it and it helped. But in the end, there was to much play in the bearings and it would slow down or even stop a couple times. New combustion blower fixed it.

Not saying to buy a new motor, just make sure the bearings are o.k.. No freeplay or wiggle. If you spin the motor, does it "feel" o.k.?

Very possible its a thermal shutdown. Just another observation that I have had personally.

Yes that is one thing on the list. But if that blower is sucking air through crud in the stove or out through crud in the vent from the blower on out it will get very hot where it is. At 475 degrees most combustion blowers say take a hike and there goes your vacuum and pellet feed and the stove heads for shutdown.

 

[heat seeker]

If the fan is just slowing, not stopping, I'd say the motor is not thermalling off. Monitor the voltage going to the motor when it's running slow. If it's the same (or close) to the voltage when it's running fast, the motor is at fault, and it's probably worn/gummy bearings. If the voltage is much lower, something in the control is quitting after it gets hot enough.

 

[pellethunter]

Did you remove the 2 metal panels behind the firebrick and clean the ash behind there?

 

[Stovensen]

Obviously something is causing the fan to slow/shut down once the stove gets hot. What's the best place to start for chasing electrical?

Most likely a worn out Triac:

The Triac output signal possibly gets distorted when the Triac gets hot after some time. This can only be determined be analyzing the signal fed to the combustion blower by means of an oscilloscope.

If this distortion cuts off one half of the 60 Hz wave... then the motor is fed with a pulsating dc-signal, which will stop the motor and overheat it, until the built-in thermal protection shuts it down.

The DSO nano handheld scope is fairly new on the market. I bought one a couple of months ago. It has almost the same look and size of an iphone. $45,- on ebay:

http://www.ebay.co.uk/itm/ARM-DSO-N...25432?pt=BI_Oscilloscopes&hash=item1e5bde78b8

Owners manual for the DSO Nano handheld scope:

http://www.wide.hk/pdf/ARM_DSO_M.pdf

It comes with a 1:10 probe which is absolutely needed when measuring 120 V grid voltages, since the DSO Nano scope only can handle max. 80 V peak-peak on its input.

I also have a high quality Tektronix scope and decided to make an comparison between these two scopes, so I attached the DSO Nano scope with a piece of duck tape under the screen of the Tektronix scope.
Both are fed the same signal... the Triac output to the convection blower on my Whitfield Quest Plus stove. The two pics below show the signals at the lowest and the highest settings.
The signals are very healthy on my stove... perfectly symmetrical. Also, we can see that even at the highest setting, the blower is not fed the full unchopped 230 V/50 Hz ( Europe ) sine wave.
A dampened oscillation occurs whenever the signal is chopped because the motor is an inductive load. This happens on both the positive and the negative wavehalves.
Although the Tektronix scope has much more sharpness and detail in the picture, the DSO Nano picture is absolutely detailed enough to determine whether the Triac has "gone south" or not.
It may be a bit difficult to get access to the CB blower output signal on Smyler316s Advantage stove, since it has the older rotary knob controlboard. On the newer touchpad boards the test points are placed very service friendly on the front of the control board securely hidden under four nylon plugs.
Take care, 120 V/60Hz can be dangerous if you decide to test it yourself.

Good luck and keep us posted

 

[SmokeyTheBear]

Now that Stovensen has brought up heat and its impact on triacs, perhaps the Op can show us the insulation situation in that stove.

I remember someone who was getting an old stove back into operational shape and had stripped some insulation out, then he changed the firing rate on the stove and took out his control board and his convection blower motor.

 

[smyler316]

Vent system- new pipe. 3 inch single wall surrounded by 4 inch single wall....tight budget and couldn't find the right pellet pipe angle pieces to accomplish the routing I needed anyhow. I'll upgrade to pellet pipe as soon as I can get all the right parts. 45 degree horizontal/22 degree upward bend right out the back of the stove, 14 inches of upward pipe, 22 degree vertical bend, 16 inches of horizontal run through the wall thimble, wall vent without screen. All seems sealed with RTV high temp...no leaks.

No free play in bearings that I can feel. Motor spins smooth and quiet. Not sure how freely it should spin...maybe feels a little sticky.

Roommate pulled the panel behind the right side firebrick but said he couldn't get the left one out. I'll try again.

Triacs...what are they? Potentiometers associated with the control knobs?

Photos of insulation at....
http://photobucket.com/pelletstove

 

[Stovensen]

Here's some great info on triacs:

http://knol.google.com/k/electronic-circuits-design-for-beginners-chapter-15#

But, it may be to risky for you to play with the electronics if you don't have enough experience. You can have your original control board rebuilt at WoodHeatStoves.com for $250,-

http://woodheatstoves.com/advantage-ii-control-panel-rebuild-service-p-4270.html

This may be the safest way to go, if it turns out that the control board is faulty.

 

[SmokeyTheBear]

What is terminating that horizontal vent? If you are going straight out and do not have a proper termination you can have issues with back pressure due to the wind and guess what can happen.

Two things come to mind right off the bat.

1. The pressure switch could open causing loss of pellet feed and the stove heads for shutdown if the loss is of long enough duration.

2. There could be enough back pressure to cause the exhaust system to exceed the magic 475 degrees at the blower and the thermal trip on the blower.

I tried doing a evl calculation and what I come up with is close to 13 depending upon which tables I use, now what is your elevation above sea level?

 

[SmokeyTheBear]

I also took a look at the pictures you posted and the insulation looks decent and likely the temperatures around the control are fine. You can check it to be sure if you have the means to do so.

You also need to be certain that the convection fan is running high enough to keep the stove from doing a high temperature shutdown, hopefully, the high temperature snap discs haven't been bypassed.

 

[smyler316]

Elevation is around 2300. The pellet feed hasn't ever stopped that I'm aware of.

The pipe terminates at a wall cap....dryer vent style. I've been sure to keep the convection fan turned up to prevent overheating. All the snap switches appear to be wired properly.

It seems that airflow restriction was the culprit. I pulled the firebricks and panels and cleaned everything out. I also attached a chunk of garden hose to the shop vac and got as much ash as I could out of the area around the heat exchangers.....there was a lot up there. So far, so good. Burned all night.

If the combustion fan thermally trips, will it shut down immediately or is it possible that it would slow down first until it got hotter before stopping completely?

Anyhow, thanks for all the help everyone. I've learned way more about pellet stoves in the last week than I ever thought I would need to know. Most importantly, the simplest answer is probably the right one and simplest answer is "do more cleaning dummy".

I can appreciate Snowy Rivers' liking for simple control systems...easy to tell what's wrong.

Any follow up thoughts and advice....please send em my way.

Thanks again!
Tyler

 

[DexterDay]

A clean stove is a happy stove. Although most people think they do a good job cleaning there stove, they often overlook the path that the exhaust must take to get to the combustion blower. This is the biggest culprit of a lazy flame, because the combustion blower must pull the air through the burn pot. With that area blocked, its veru hard to do so.

Congrats on the good burning stove. And when in doubt read Forum member Krooser's signature. 80% of all stove problems are a dirty stove.

Also. The thermal trip will most likely shut it down. It may slow a little.

Knowing how the stove truly functions and what must happen for complete combustion is the best information a pellet burner can possess.

Again, Congratulations. Now you know what your stove can really do. Looking forward to further observations from you. Whitefields are great stoves and one of the early Manufacturers to jump on board with pellets. Keep it clean. At least every ton do a Good Cleaning. With mild cleanings every week or two.

 

[pellethunter]

Many don't know to remove the 2 metal panels behind the fire brick on the whitfield, for cleaning. This is the final path for exhaust and good airflow. At some point consider taking the the exhaust fan off(have a new gasket ready if needed) and give the fins a good cleaning for better flow and less wear on the motor. Glad to hear your up and running.

 

[SmokeyTheBear]

We don't mind providing the information.

When a combustion fan trips out due to temperature it can do one of two things actually stall completely (this can lead to other problems) or shut itself off. In both cases the motor restarts when the temperature drops enough. If it is a stall situation it is the same as one of the control system triacs failure modes and can if allowed to happen frequently destroy its controlling triac.

Theses stoves are very simple devices two air pumps, a fuel feed, and a place inside the plumbing of one of the pumps for the fuel to burn.

The end result is a system that is more prone to problems with plugged plumbing than the electronics or mechanical parts.

The primary reason a lot of stoves find their way to the used market is because people didn't keep up with nor were going to bother keeping them clean.

krooser's sig says it all: 80% of all pellet stoves problems are due to dirty stoves.

I like to say a clean stove is a happy and safe stove.

Enjoy the heat.

 

[smyler316]

I'm loving the heat! Smelling a little smoke though. Seems to be strongest behind the stove. I think I might need to reseal the pipe/stove junction. Think I need to order new firebrick soon as well. The chunk missing from the top of the right piece is big enough that I think it's gonna let ash build up pretty fast. There's also a pen sized hole in the center brick just above the burn grate.

 

[SmokeyTheBear]

I'm loving the heat! Smelling a little smoke though. Seems to be strongest behind the stove. I think I might need to reseal the pipe/stove junction. Think I need to order new firebrick soon as well. The chunk missing from the top of the right piece is big enough that I think it's gonna let ash build up pretty fast. There's also a pen sized hole in the center brick just above the burn grate.

If you are patient you can use retort cement to buildup up the "firebrick" you apply a little at a time, air cure , and then let it heat cure. The application is done outside the firebox on a surface that the cement won't stick easily to or you can pull off after it has somewhat air cured. Then you fire it in the stove.

You can find a leak easily by starting with a cold stove, start it and when the smoke starts in the firebox and the lights are off run a strong flash light along the exhaust system and venting.

 

[smyler316]

I need to get a better flashlight first.

Don't have the time to rebuild my firebrick right now. I've seen about 3 different firebrick options so far. The OEM, an aftermarket on woodheatstoves.com, and an aftermarket "cerra" on ebay.
Any reccommendations?

 

[SmokeyTheBear]

Nope, on my stove they are optional decorative and long ago relegated to a garage shelf along with the fake log.

 

[smyler316]

Aggghhhhhhhhhhhhhh

Ok, I got about a day and a half of awesomeness before the lazy burn came back sometime last night. Tried to relight it and the combustion fan would barely move. "F this"....I went back to bed. Tonight I did a quick check/clean out and everything looked fine. Turned on the fans and got a low "idle" speed turning from the combustion fan. Messed around with the heat setting dial a few times, started and stopped the fans a few times and the fan started running fine again. Removed the CSR from the system...seems to have 0 effect on anything. I plugged the fan directly into an outlet....spun really slow for about 5-10 seconds before speeding up to normal speed. Unplugged/plugged it a couple times and the fan spun right up. I plugged the fan back into the stove (ran fine) and took some voltage readings from post #4 on the terminal strip. 12-13 volts on heat setting 1 and 24-25 volts on heat setting 5. Plugged it back into the wall for about 2 hours and it ran fine.

I'm getting the feeling that the fan motor is getting tired.

Would something going bad on the board cause similar symptoms?

Help! My wife is cold...

 

[SmokeyTheBear]

Aggghhhhhhhhhhhhhh

Ok, I got about a day and a half of awesomeness before the lazy burn came back sometime last night. Tried to relight it and the combustion fan would barely move. "F this"....I went back to bed. Tonight I did a quick check/clean out and everything looked fine. Turned on the fans and got a low "idle" speed turning from the combustion fan. Messed around with the heat setting dial a few times, started and stopped the fans a few times and the fan started running fine again. Removed the CSR from the system...seems to have 0 effect on anything. I plugged the fan directly into an outlet....spun really slow for about 5-10 seconds before speeding up to normal speed. Unplugged/plugged it a couple times and the fan spun right up. I plugged the fan back into the stove (ran fine) and took some voltage readings from post #4 on the terminal strip. 12-13 volts on heat setting 1 and 24-25 volts on heat setting 5. Plugged it back into the wall for about 2 hours and it ran fine.

I'm getting the feeling that the fan motor is getting tired.

Would something going bad on the board cause similar symptoms?

Help! My wife is cold...

I need to find a voltage chart but if you are only getting 25 volts at maximum things aren't right. Full out should be line or damn close to line voltage.

Are the parts visible on that control board, if so snap a good picture and post a link to the picture just like you did with the insulation.

The CSR is a safety device that was declared redundant and subsequently removed.

 

[DexterDay]

My 16 yr old Englander had a bad bearing and started to slow down. If I cocked the motor the right way, it would run full bore.

This is the motor I bought for it. Its a Fasco A082. Less than $100.

http://www.cshincorporated.com/product_info.php/products_id/3462

How old is your unit?

 

[SmokeyTheBear]

You said you put a couple of drops of oil into each port, would you put a couple more drops into each port it is possible there isn't enough lubricant. You have no idea how long the unit went without service.

I'm having trouble finding the voltage chart, one of the links is no longer available.



Between this forum mangling of links and google fits a google search for whitfield advantage pellet stove combustion blower voltages and select the quick view on this SERP entry:


y g ~ T -— V W _ V A _, EXHAUST BLOWER MOTOR '“ “QUICK ...
www.woodheatstoves.com/.../PP7600_12056010 instructions.pdf
File Format: PDF/Adobe Acrobat - Quick View
Combustion Exhaust Motor. ... Whitï¬eld® Advantage series pellet stoves, along with factory ... has a digital control board with combustion voltage adjustment ...

 

[smyler316]

Stove was off all last night and today. Got home and plugged the blower directly into the wall hoping that I could just run it separately and fire the stove up see how it went. The fan didn't move for about 5 seconds, started spinning slowly for about 20 seconds and then finally sped up to normal speed. I'll put some more oil in it and see how it does but I think I need a new blower motor.

Thanks for the info on voltages. I also took voltage readings from the convection fan and got similar readings....they ranged from 1.1 at full speed to 56 at minimum speed. When I took voltage readings for each fan I took them at both posts. One post showed a range and the other always showed 120v for both fans.

After looking those voltage settings I think I need to make some adjustments to my auger feed as well. The off time on setting #1 is about 11 second...no wonder I can't keep the stove running on that setting. I could use some info on making those adjustments. The board is a little out of my "dive in and go for it" comfort zone.

And just to make sure I'm not an idiot...when I took my readings I touched the negative lead of my voltmeter to a bare screw on one of the body panels.

 

[SmokeyTheBear]

I'd start by making sure that combustion blower has full lubrication. This is one of the hazards of getting a used unit you already know it was put away dirty.

While playing with the blower, order a new one.

The board would be the last thing I'd suspect. I'd do my playing with a direct connect to line voltage. The motor should start every time and get to full speed very quickly.

 

[smyler316]

I'd start by making sure that combustion blower has full lubrication. This is one of the hazards of getting a used unit you already know it was put away dirty.

While playing with the blower, order a new one.

The board would be the last thing I'd suspect. I'd do my playing with a direct connect to line voltage. The motor should start every time and get to full speed very quickly.

Ya...I rigged a quick connect so I can plug it straight into the wall. Should I avoid getting a motor from the local electrical supply? The guys here are pretty good. I work at a ski area and they've gotten all sorts of random stuff for us over the years.

 

[SmokeyTheBear]

I'd start by making sure that combustion blower has full lubrication. This is one of the hazards of getting a used unit you already know it was put away dirty.

While playing with the blower, order a new one.

The board would be the last thing I'd suspect. I'd do my playing with a direct connect to line voltage. The motor should start every time and get to full speed very quickly.

Ya...I rigged a quick connect so I can plug it straight into the wall. Should I avoid getting a motor from the local electrical supply? The guys here are pretty good. I work at a ski area and they've gotten all sorts of random stuff for us over the years.

Whatever you get it must match the electrical specifications and rpms of your current unit.