St.Croix revolution vacuum issue

[Beetle]

Beetles experimentation continues......

8 feet of 1/2" id tubing from the vacuum switch stub to outside air, same as combustion air...been running on program 4, heat 5 for two hours....no fluctuation in the ohm needle, pop it off and the tester goes wild... could it be...? or just restriction from the 8' tube..? wanted to put my Vacuum gauge on it record fluctuation, cant find the damn thing..

I agree this is telling something...what, however, is the question..

Gonna let in run thru the night on level 4 with tube attached and see what happens....stay tunned.

 

[SmokeyTheBear]

He he.

 

[heat seeker]

I sure doubt you're getting much restriction from ½" ID tubing. After all, there's no real airflow in there, just a very minute movement to adjust for pressure change. Looks like you're onto something, Beetle!

Question: what are you looking for with the ohmmeter? I think the vacuum sensor is just a switch, not a pot, so it would be on or off, nothing in between.

Also, my Afton Bay needs to lose vacuum for 45 or 60 seconds (depends on where you read the book) to get a vacuum loss shutdown.

 

[SmokeyTheBear]

I sure doubt you're getting much restriction from ½" ID tubing. After all, there's no real airflow in there, just a very minute movement to adjust for pressure change. Looks like you're onto something, Beetle!

Question: what are you looking for with the ohmmeter? I think the vacuum sensor is just a switch, not a pot, so it would be on or off, nothing in between.

Also, my Afton Bay needs to lose vacuum for 45 or 60 seconds (depends on where you read the book) to get a vacuum loss shutdown.

He is using the ohmmeter as a continuity meter ... I'd do a voltage measurement across the switch terminals ... but if it works it works.

 

[heat seeker]

I'd measure voltage, too, while the stove is running. If the switch opens, it would sure confuse the ohmmeter, although I think it's only 5 volts logic. A recording chart meter would really be cool...

 

[Beetle]

the ohm meter is only showing that the switch is opening and closing erratically...kinda stumbled on it while checking the switch to see if it was operating.

 

[SmokeyTheBear]

the ohm meter is only showing that the switch is opening and closing erratically...kinda stumbled on it while checking the switch to see if it was operating.

Yes we understand what you are doing, however the meter in ohm mode does put a voltage across the contacts, this is from the battery in the meter.

 

[heat seeker]

I think Beetle's using an analog meter - right Beetle? In post #50 you mention the meter needle going wild - that would probably be from voltage being applied to the ohms function of the meter. And that could easily blow the meter movement. I agree with Smokey that the voltage from the meter battery could be confusing the stove controller.

 

[Beetle]

agreed...but why the change from erratic to fully closed switch by choking the draft or mucking with that protruding vacuum tube??

 

[SmokeyTheBear]

Oh I don't think that the voltage from the meter is confusing anything it simply isn't the way to check the switch in circuit.

Your test is working for what you are doing Beetle.

 

[heat seeker]

Choking the draft would increase the vacuum inside the firebox, making the switch.

The vacuum tube is a puzzler, and I think it needs to be vented to the outside. For whatever reason, you may have a reduced pressure in your basement. Even wind blowing over the old chimney can reduce the pressure in the basement. Any exhaust fan running would, also, such as Radon remediation. I doubt you run your clothes dryer all night, so that's out.

I think it's already been mentioned that a restriction in the venting would reduce the vacuum in the firebox, as would a lazy or defective combustion blower.

Please define "erratic" for us - the switch should be on or off. If it's flakey, you've a bad switch or diaphragm, etc.

 

[Beetle]

Erratic...meter needle swinging wildly left to right to center etc. etc. New switch from dealer.

I know this is not a valid method.....but ii believe it is showing the vacuum/pressure at the switch is close to neutral...switch opening and closing rapidly because of slight swinging from positive to negative. So the question is why is neutral pressure on 4 and 5 setting only...?

Gonna find that vacuum gauge....that will tell the story.

 

[SmokeyTheBear]

The voltage range with 120 VAC in it is the proper way to do the in circuit as the switch when open could have a substantial fraction of 120 (please note the weasel word could) on it, the meter reading zero would indicate a closed switch and above that an opened one.

 

[heat seeker]

It sounds to me like the switch is bouncing open and closed because the vacuum is at the critical point, and may be fluttering.

Why - that's the whole problem.

If the meter doesn't respond on the 120 VAC range, look for a low DC voltage. I'm not sure, but I think the switches on my Afton are all 5 VDC. I know the POF switch is.

I still think there is a problem somewhere between the combustion blower and the outside world, that is cutting down the airflow needed to maintain the vacuum. This really has my curiosity piqued!

 

[Beetle]

Even Temp replied to my email..imagine that. However, no advise given other than have my dealer come out and take a look.. which is next on the list anyway.

 

[SmokeyTheBear]

Even Temp replied to my email..imagine that. However, no advise given other than have my dealer come out and take a look.. which is next on the list anyway.

Well they must be paying attention to something for some reason.

Glad you got a response and that they want the dealer involved.

 

[slangtruth]

Even Temp replied to my email..imagine that. However, no advise given other than have my dealer come out and take a look.. which is next on the list anyway.

Just for giggles I'd try to have the dealer's tech call Even-Temp before he actually makes the trip, and ask why the vacuum switch uses a floating reference point with two hoses rather than one, like most stoves. Wondering if there's a good technical reason to do it that way.

 

[SmokeyTheBear]

Even Temp replied to my email..imagine that. However, no advise given other than have my dealer come out and take a look.. which is next on the list anyway.

Just for giggles I'd try to have the dealer's tech call Even-Temp before he actually makes the trip, and ask why the vacuum switch uses a floating reference point with two hoses rather than one, like most stoves. Wondering if there's a good technical reason to do it that way.

ROTFLMAO.

 

[slangtruth]

I'm serious, no laughing. I used to work in manufacturing. Our products were engineered a certain way and certain choices made for a reason, and that reason wasn't always to lower costs. I'd want to know the reason before I decided to hot rod around it.

 

[SmokeyTheBear]

I'm laughing at the look on the tech's face when a customer makes that request.

I'm well aware of things being made a certain way for a reason. Doesn't mean the way they were made corresponds to what was intended but didn't get translated correctly. It isn't confined to hard goods manufacturing.

 

[Beetle]

I have no intention what so ever to hotrod around it.....I save that for my SB Chevy's, 1=261 stovebolt, 1=283 with 2 spares, 1=327, and 1=350.

 

[Beetle]

Vacuum is suspect...but why..?

1st shot heat level 1, draft 30%, needle steady.
2nd shot heat level 5, needle wild between -0.06-0.1 cw.

As I understand the switch opens at -0.05 cw.
St.Croix stoves designed to operate between -0.10-0.30, Quote " a reading less than 0.10 negative pressure is marginal and requires a closer look "

Best I can get out of it is 0.1 at high heat with draft closed about 90%, very lazy burn.
Checked combustion fan voltage at the same time I was going thru the heat levels, voltage climbs from 90-125.

Vent ??

 

[heat seeker]

Vent, defective fan, blockage or restriction in the exhaust path. Don't know if anyone mentioned the termination cap yet.

 

[Beetle]

Vent is what I am thinking...what about the termination cap?

 

[smoke show]

Vent is what I am thinking...what about the termination cap?

plugged or restricted.