Honeywell Pressuretrol setting

guzzinerd

These are the settings on my Bryant 245-8.  Are they ok?  If not, how do I adjust this thing?

Thanks

EdTheHeaterMan

Looks a little high to me.
look here https://heatinghelp.com/systems-help-center/how-to-set-and-adjust-the-boiler-pressure-control/
there are screws at the top that adjust the two scales. 2 PSI is the max I would set on a residential heating system. The cut in should be about .05 PSI

guzzinerd

When you say cut, you mean the diff. pressure?  

Lowered the main to 2

guzzinerd

Like this?  Sorry not sure what you mean by cut.. is it the diff?

Waher

The "diff is subtractive" side on the left means subtract this diff # from the # on the right to get the "cut-in" #.
So on the right the "2" set on the Main is the "cut out" pressure, to set the cut-in on the left you want it lowered to a DIFF of 1.5

This will give you the cut in pressure of 0.5PSI with the cut out at 2psi.

The adjustment screws are on the top of the pressuretrol on the back left side.

guzzinerd

Waher said:

The "diff is subtractive" side on the left means subtract this diff # from the # on the right to get the "cut-in" #. So on the right the "2" set on the Main is the "cut out" pressure, to set the cut-in on the left you want it lowered to a DIFF of 1.5 This will give you the cut in pressure of 0.5PSI with the cut out at 2psi. The adjustment screws are on the top of the pressuretrol on the back left side.

Got it. So if the min diff on this gauge being 2 i just set it a bit below like so?



And should I hang around and wait for it to cycle on to make sure the new settings didn't hurt anything?

EBEBRATT-Ed

Yes hang around for a couple of cycles.

You might lower the main just under 2. You want the burner to cut back on just before the gauge hits 0.

But try what you have for now. The pressure control settings are inaccurate usually so you may have to fiddle with it a couple of times to get what you want

guzzinerd

EBEBRATT-Ed said:

Yes hang around for a couple of cycles. You might lower the main just under 2. You want the burner to cut back on just before the gauge hits 0. But try what you have for now. The pressure control settings are inaccurate usually so you may have to fiddle with it a couple of times to get what you want

Ok.  I assume if i don't hear any banging and hissing it's ok then? It was quiet with the original settings.

guzzinerd

Ok, the burners are still on and the round gauge is over 3, shouldn't they cut out around 2?  Is this the inaccuracy you guys spoke of?

While sitting here the burners shut off for about 10 minutes and then turned on again while the usg gauge didn't budge.  Actually, it's barely ever been below 3 an sits close to it when everything is off, could the gauge be defective?



And if it is defective what do you recommend as a replacement?

EBEBRATT-Ed

I assume you checked the pigtail and it is clean. Yes the gauge could be off or it could be the pressure control scale inaccuracy. Only a new gauge can tell you. I would put a 0-30 lb gauge (code required and a 0-5 psi gauge on it with a valve under the 0-5 psi gauge only

guzzinerd

EBEBRATT-Ed said:

I assume you checked the pigtail and it is clean. Yes the gauge could be off or it could be the pressure control scale inaccuracy. Only a new gauge can tell you. I would put a 0-30 lb gauge (code required and a 0-5 psi gauge on it with a valve under the 0-5 psi gauge only

I have not checked it.  Will remove it and use a zip tie and some compressed air to check it out.

Ok, so a new gauge with 0-30 psi scale and a 0-5 gauge with a shut off valve and put them on a t?

Thank you

guzzinerd

EBEBRATT-Ed said:

I assume you checked the pigtail and it is clean. Yes the gauge could be off or it could be the pressure control scale inaccuracy. Only a new gauge can tell you. I would put a 0-30 lb gauge (code required and a 0-5 psi gauge on it with a valve under the 0-5 psi gauge only

Checked the pigtail today and was clear.  The pressure gauge sits at 2.5 even when removed so i replaced it with a new 0-30 Campbell i picked up at the local hardware store.  No one local had an LP gauge so that's on the way from an online supplier.

I removed the pressuretrol and bench tested it using an air pump.. it's clicking at around 2 psi and again under 1 psi so i assume it's working ok.  I also tested the wiring by removing one of them from the burner control and it stopped it from starting up, so that checks out ok.

I hope the problem was just a defective pressure gauge (it was registering close to 6psi before shutting off last night), will know this evening when it cycles up again.

Alex

guzzinerd

Been watching the meters and i have main on the trol pretty much bottomed out before it shuts off the burners, close to 4 psi.  The diff setting turns it back on when it's back down to 0. 

Not sure if it's the cheap gauge or inaccurate trol.   I'll check again with the LP gauge when it arrives next week.  The pigtail is clean, what else should I be checking?

Thanks 

EBEBRATT-Ed

That's about all you can do. You might take the p troll off again and check down inside the pipe thread for any debris. It should get lower than 4 psi

guzzinerd

EBEBRATT-Ed said:

That's about all you can do. You might take the p troll off again and check down inside the pipe thread for any debris. It should get lower than 4 psi

I'll give that a try. 

Is it possible that the main cut off gets sticky?  

Also noticed that this MoM near the boiler, above the Dunham trap, is venting a lot at the end and start of each cycle.. that normal?  Should it get a larger vent maybe?

neilc

something seems off there,
that main turned all the way down is your cut out, ( 0, ? ),
and the subtractive diff is the cut in, (1), 0 - 1 = it shouldn't be turning on,
If you pull a wire from the trol does the boiler fire ? it should not,
if you take that new gage off, it does zero out ?
then can you breath down thru the gage hole and freely breath into the boiler?
maybe the top valve on the sightglass is plugged, or the bottom valve also?
you do want that main scale up closer to 1.5 / 2, but find why the gage is up, and why the trol set as it is, is allowing the boiler on

guzzinerd

neilc said:

something seems off there, that main turned all the way down is your cut out, ( 0, ?)

Yes!

, and the subtractive diff is the cut in, (1), 0 - 1 = it shouldn't be turning on, If you pull a wire from the trol does the boiler fire ?

No, shuts the burner off when i removed the wire.  The boiler does fire up again after hitting zero psi for a while 

 it should not, if you take that new gage off, it does zero out ?

Yes, goes to zero

then can you breath down thru the gage hole and freely breath into the boiler?

Haven't tried that but i did remove the pigtail and was clear and also looked down into the LWCO and was crusty but clear.  The sight glass valves work ok, not stuck. In fact, changed the glass rubbers less than a year ago.

maybe the top valve on the sightglass is plugged, or the bottom valve also? you do want that main scale up closer to 1.5 / 2, but find why the gage is up, and why the trol set as it is, is allowing the boiler on

It's what I'm trying to do.  Tomorrow I'll remove the trol again and make sure there aren't any obstructions

Everything is working pretty well otherwise, just trying to get it to shut down before hitting 2psi.

guzzinerd

Is it possible that the previous trol main setting at 5 was so high that it was the thermostat to shut the burner off and on for so long (years) causing the trol switches to get sticky from non-use?

neilc

take the pigtail off again and poke something long and thin all the way down into the LWCO,
might be worth taking the whole Y fitting and checking all 3 ports to the Y,
and the connections back to sightglass valve, LWCO, and up to the piggy,
and then, the 2 glass valves back into the boiler

Jamie Hall

That is a subtractive, not additive, pressuretrol, Says so, right on it. On that type of pressuretrol, the right hand scale is the CUTOUT pressure, nor the cutin, and the left hand scale is the differential, which is subtracted from the cutout on the right hand scale to obtain the desired cutin pressure.

With the pressuretrol set as shown in your photo, it should never cut in and the boiler shouldn't run at all. If the boiler does, there may be something seriously amiss with the wiring of the controls (it's set to cut out at atmospheric pressure -- 0 -- and cut back in at a vacuum of 1 psi -- which it will never reach).

guzzinerd

Jamie Hall said:

That is a subtractive, not additive, pressuretrol, Says so, right on it. On that type of pressuretrol, the right hand scale is the CUTOUT pressure, nor the cutin, and the left hand scale is the differential, which is subtracted from the cutout on the right hand scale to obtain the desired cutin pressure. With the pressuretrol set as shown in your photo, it should never cut in and the boiler shouldn't run at all. If the boiler does, there may be something seriously amiss with the wiring of the controls (it's set to cut out at atmospheric pressure -- 0 -- and cut back in at a vacuum of 1 psi -- which it will never reach).

I understand that.  When the pressure was around 4 psi it wasn't cutting out so i started lowering the main setting on the trol until it did cut off... Near the bottom, since then it's been cutting off around 4 with it set where it is.

I've been sitting here watching it for a couple hours now....the last couple cycles came and went at zero pressure so i think the thermostat is running things since it's not very cold outside tonight (40° now).  Going home and will look at it all again tomorrow.

Thanks 

Just had a thought.  When i originally tried lowering the main setting from 5 to 2 the screw was raising up out of the box instead of pushing the indicator down... Pushing down on the raised screw did lodge the indicator loose.. could that have maybe messed up the calibration?

Jamie Hall

Yes -- the screw should only raise or lower the indicator and the associated links inside. I'm going to say that something inside that pressuretrol has come undone. It happens. Whether it's fixable or not depends a lot on how clever a mechanic is working on it. One caution, though -- the wiring may be 120 volt, so I'd only take the cover off and poke around with the power turned off.

guzzinerd

Jamie Hall said:

Yes -- the screw should only raise or lower the indicator and the associated links inside. I'm going to say that something inside that pressuretrol has come undone. It happens. Whether it's fixable or not depends a lot on how clever a mechanic is working on it. One caution, though -- the wiring may be 120 volt, so I'd only take the cover off and poke around with the power turned off.

.not surprisingly, found instructions from an old heating help thread:

https://forum.heatinghelp.com/discussion/149944/i-figured-out-how-to-calibrate-a-pressuretrol

This is literally the friendliest, most helpful forum I've ever encountered.

ethicalpaul

Also noticed that this MoM near the boiler, above the Dunham trap, is venting a lot at the end and start of each cycle.. that normal?

that's its job!

Should it get a larger vent maybe?

Shut off the boiler in the middle of a call for heat, let it sit for 5 minutes, start it up, start a timer, and see how long steam takes to get to the vent.

guzzinerd

ethicalpaul said:

Also noticed that this MoM near the boiler, above the Dunham trap, is venting a lot at the end and start of each cycle.. that normal?

that's its job!

Should it get a larger vent maybe?

Shut off the boiler in the middle of a call for heat, let it sit for 5 minutes, start it up, start a timer, and see how long steam takes to get to the vent.

Just saw your reply @ethicalpaul.  I know that's the vent's job.  I mentioned it because it was whistling, not super loud but enough that it would be a problem in a living space instead of the boiler room.  I stuck a Gorton #2 and can still hear it vent if i listen but it's more of a quiet whooshing now.  I thought it was near impossible to over-vent, am i wrong in this case?