25 PDVC vacuum test

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N.E S4

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Nov 28, 2012
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Has anyone done a vacuum test before. I was told by Englander tech but was not clear. I was told to disconnect the lead from the switch closest to the exhaust. Connect it together and run the stove, if you get E1 code that means the vacuum switch is bad. Is this correct?
 
No, you could have airflow problems that the vacuum switch is detecting. These switches rarely go bad. Jumping the switch out defeats the safety feature, so the stove shouldn't be run for long like that. It just narrows down the search for your problem.

Give us more details, there is lots of help available here!
 
No, you could have airflow problems that the vacuum switch is detecting. These switches rarely go bad. Jumping the switch out defeats the safety feature, so the stove shouldn't be run for long like that. It just narrows down the search for your problem.

Give us more details, there is lots of help available here!

I fixed the vacuum leak and still have E-1 code. I'm trying to determine if the vacuum switch is bad or not.

I went ahead and replaced the combustion motor and bypass the vacuum switch. It's been running for over 3 hours now without any issue. I think it was the combustion motor that was bad. It stop when it gets too hot.
 
That would do it!

A better way to test the vacuum switch is with a mulitmeter.

The real test for you now is whether the stove runs with the jumper removed. Please don't run the stove any longer with the jumper in place.
 
Just shut it down, I'll fire it back up tomorrow night without the jumper. I only run the stove in the evening during the week. I'm kicking myself in the Ass for not buying a new unit.

I paid $475.00 for this unit and already put $350.00 into it in 2 weeks, plus 2 spare auger motors at $140.00
 
You should also check for plugged or leaking vac hoses. They can cause the same symptoms.
 
Update on my stove. After checking for all vacuum lead, replaced the combustion motor the stove still have E1 code. Now I've narrow it down to the vacuum switch. I've bypassed the lead to the vacuum switch the stove run very well at all heat range. When I plug the lead back on the switch it ran fine at 2 heat range. I bump it to 5 it shut down with E1 code. I unplug the stove, plug it back it bypass the vacuum switch it ran fine all night.

The vacuum switch can go bad. I had though it was the combustion motor, now I have a spare.
 
You could still have a blockage, either in the stove or the venting. I'd say you have a blockage in the venting, since at lower flow rates, you maintain enough vacuum to satisfy the switch, but a higher flow rate, you lose the vacuum.

I assume that the tubing to the vac switch is good, and the ports at both ends are clear.

While it's certainly possible the vac switch is bad, I'd check all the venting from the combustion fan out to the cap before buying a new one.
 
You could still have a blockage, either in the stove or the venting. I'd say you have a blockage in the venting, since at lower flow rates, you maintain enough vacuum to satisfy the switch, but a higher flow rate, you lose the vacuum.

I assume that the tubing to the vac switch is good, and the ports at both ends are clear.

While it's certainly possible the vac switch is bad, I'd check all the venting from the combustion fan out to the cap before buying a new one.

It can't be blockage in the vent? I've just install the stove 2 weeks ago and the exhaust pipes are all new. I've inspect all the vacuum hose it's all in excellent condition. I've confirm with Englander's tech he agree it's the vacuum switch. I only run the stove in the evening just to help supplement the gas bill a bit.

This stove was made in 2004, all the previous owner did was replaced a few gasket as recommended. The only part that need replacing is the vacuum switch all the motors works fine. This is a true working man's stove. I bought the combustion motor because the tech at Englander told me the parts that go bad on this stove is the combustion motor and the arguer motors. My lack of experience with the stove lead me to replacing the combustion motor when I got the E1 code. With further trouble shooting it's the vacuum switch.

Since 2004 and all it really need is a vacuum switch what more can you ask for. The motor are a bit noise but a few new bearings will take care of that.

Over all I'm happy with the stove. It keeps my basement warm at 80 degree with heat range setting at 5 and blower setting at 7.
 
Okay, I hear you.
One more question - or two - has the stove ever run properly since its installation?

If not, you may want to check the EVL of the venting.

If so, then I agree, the switch is suspect.
 
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It can however be crap in the exhaust system of the stove which starts just above the burn pot.

How did you clean the stove before you installed it?
 
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You can hurt yourself leaping from one conclusion to another.
 
Okay, I hear you.
One more question - or two - has the stove ever run properly since its installation?

If not, you may want to check the EVL of the venting.

If so, then I agree, the switch is suspect.

The first day it ran fine but I never set the heat range over 4.I've been having issue once the heat range 5 or higher.

I've been running it at 5 or lower, but with the vacuum switch by pass it was set at 7 without any issue, but I haven't gone up to 9 yet.

Last night I plugged back the vacuum lead it shuts off at 4, right away I unplug the stove by pass the vacuum switch fired it back up it ran fine all night.

The tech at Englander also confirm it's the switch. Tonight I will clean the tube that connect the vacuum hose to the combustion housing and run the unit with the vacuum lead plug. If it shuts down then I'm 110% sure it's the switch.
 
It can however be crap in the exhaust system of the stove which starts just above the burn pot.

How did you clean the stove before you installed it?

That section was clean very well before I install the unit. I vacuum the stove daily and I've cleaned back there twice in 2 weeks. When I removed the combustion housing for new gasket I've also cleaned the inside of the combustion housing and the path way up to the stove. I only run the stove for about 5 hours daily it can't be plugged.

Tonight I will clean the small tube that connect the vacuum hose to the combustion housing.
 
Sounds like you're in the market for a new vac switch, after all. Worst that can happen is you'll have a spare.

Could you describe your venting, from the stove out, such as diameter, lengths, elbows, T's, etc? We can then figure out your EVL ("we" meaning the gurus here, I'm not sure of the numbers….).
 
Last night I plugged back the vacuum lead it shuts off at 4, right away I unplug the stove by pass the vacuum switch fired it back up it ran fine all night.
If your have some means of pulling a vacuum such as a syringe or a small vacuum pump you could prove conclusively that the switch is not working (you can suck on the tube while the switch is connected to a meter).
What doesn't make sense is for the switch to work up to a certain blower setting and then not work when the blower is pulling harder. I suspect a gasket that is blocking a leak until the blower pulls hard enough. Try the dollar bill test on the door gasket. visually inspect the blower gasket, do a smoke test.
Buy a vac switch if you really want to. Substitution of a known working part will tell you if it really is the switch.
 
Ok, your stove is immaculate and that vacuum switch is what at fault buy a new one.

The vacuum switch has been ordered. So far in 2 weeks I have a spare combustion motor, 2 auger motors, all the gasket that needed for the yearly maintenance.

It's been a good learning experience. For a 2004 model all it needed is a vacuum switch I say it's a good reliable stove. The previous owner properly got tired of dealing with the E-code and have a hard time trouble shooting.
 
If your have some means of pulling a vacuum such as a syringe or a small vacuum pump you could prove conclusively that the switch is not working (you can suck on the tube while the switch is connected to a meter).
What doesn't make sense is for the switch to work up to a certain blower setting and then not work when the blower is pulling harder. I suspect a gasket that is blocking a leak until the blower pulls hard enough. Try the dollar bill test on the door gasket. visually inspect the blower gasket, do a smoke test.
Buy a vac switch if you really want to. Substitution of a known working part will tell you if it really is the switch.

From what I understand the dollar bill test in the door gasket will test the vacuum switch under the control panel. That vacuum switch shuts the stove off if the door is open or lost of vacuum.

The which that I tested is connected to the combustion housing motor with it bypassed it ran fine. I don't think it's the door ajar switch, but I will also test that anyways just to cover all bases.
 
thing to remember with a vac switch is that air density matters. the higher the temperature the less dense the air is. vacuum pressure is reduced a bit with the lighter air. so the vac switch will hold until the amount of pressure is reduced beyond its ability to hold the switch closed. normally the switch can hold at relatively high temps (which have relatively low air densities) but if the switch fails due to a tear in the diaphragm it may not hold at a pressure which normally it could hold at.

so it is possible for a vac switch to hold at a lower heat range and not at a higher one
 
I only get the E1 code at higher heat range


what is happening with your stove is this,
the unit running on low settings is holding vacuum because the air temperature is still low enough (and air density therefore high enough) that the switch will still hold in the closed position. as you turn the unit up the air temp gets higher and in turn the air density gets lower, once the pressure drops below .17"inwc" or inches water column pressure, the switch would open. now, if the switch is damaged and leaks air past the diaphragm in the switch the "drop" pressure may be higher in essence dropping the switch when it really should still be holding.

this isnt the only thing that could cause the issue but it looks as though most all of the other possibilities have already been covered.

remember the velocity of airflow through the system is what creates the amount of vacuum needed so things that overly restrict the velocity of thhis air also reduce the amount of vacuum pressure available to the switch
 
I understand warmer air are less dense. I'm very new to pellet stove. When the manufacture tells me the common components that can go wrong is the combustion motor and auger motor. It lead me to replacing the combustion motor after I had replaced the combustion housing and motor gasket.

I've got it diagnosed now.
 
I've got it diagnosed now.
I don't know if you noticed that Mike Holton, who replied above, works for your stove's manufacturer. He is a resource we all look to for understanding of the stove's functioning.
 
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