Honeywell Pressuretrol model PA404A1009

briggs

Boiler pressure exceeds Pressuretrol cut out setting. Pigtail & port to diaphragm are clear.
How to test for source of trouble?
Where to find replacement parts? Not getting them from Honeywell.
Is it possible to get new replacement units for under $75. ? Where to find them at a reasonable price?
Where can we find re manufactured units?
Are there manufacturers other than Honeywell that make this device at a lower cost? Thank You.

Jamie Hall

Pressuretrols are a little notorious for being out of calibration. Not hard to fix -- check this thread:

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

However, before you do that, get an accurate pressure gauge with a suitable range on the same pigtail -- above the loop -- and make sure that the problem is the pressuretrol and not the gauge.

Replacement parts? Those are not meant to be serviceable except for calibration. Never seen replacement parts.

Best source I can think of for a new one would be Supply House -- or your local plumbing and heating supply house. But it's not going to be $75. The price from Supply House is reasonable. Keep in mind that this gadget is, in many applications (particularly if there is just one) a critical safety device. Don't skimp.

EBEBRATT-Ed

No one rebuilds or remanufacturers pressure controls due to the safety issues @Jamie Hall mentioned.

If your 100% sure the piping and pigtail is clear suspect the pressure gauge as mentioned above. Also the PA404A if I am not mistaken does not have a cut out setting directly. It has a cut in setting and a differential adjustment wheel inside the pressure control (white wheel with numbers).

You should sett the cut in with the adjusting screw on the control. Adjust this so when the burner goes off on pressure it will restart at about 1/4-1/2 PSI. Then set the differential at 1-1 1/2 psi. You should try and keep the pressure below 2 psi.

The pressure adjustment sale is not alyays reliable. Jut set it so it will work at the pressures mentioned.

You can also (gently) use a screwdriver to move the operating lever up and you should here the microswitch open and close.

briggs

Thank you Jamie for your helpful comments. Appreciate your sharing how to calibrate a pressuretrol will follow your instructions. If replacement is necessary, would a vaporstat be a better way to go?

briggs

Hi Ed,Yes cut in is set on scale front of unit. Differential adjustment wheel for cut out. With cut in set to .5lb & differential set to 1 cut out should be 1.5lb with the additive type pressuretrol. Shut down pressure can be as high as 6 - 7 lbs.
Will follow your & Jamie's suggestions to re address calibration.
Yes had concern that gauge faulty. Tested against a known source of air pressure & gauge looks ok.
Gauge mounted to a T at end of pigtail with the pressuretrol. Is Jamie saying the gauge must be located above the loop in the pigtail? What loop is he referring to? Thank You both for your help.

Jamie Hall

Yes I am. The objective of mounting the gauge above the loop in the pigtail (or other water trap for other arrangements) and in the same air space, effectively, as the pressuretrol or vapourstat is that that way you know -- from the gauge -- what the pressuretrol is actually "seeing" in terms of pressure.

Now your question about to what loop I am referring makes me wonder a little if you may have one of the alternative arrangements for protecting the pressuretrol (and gauge) from direct contact with steam. The most common arrangement is for the pipe connecting the pressuretrol to the boiler to have a full circle loop in it -- hence the name pigtail -- which traps water and creates the desired separation (it can also trap gunk, and so needs to be checked for being open now and then!). However, there are any number of other ways to configure some pipe and fittings to accomplish the same purpose. Would you be able to post a picture of your pressuretrol and the piping connecting it to the boiler?

briggs

Ok I can get a camera & get picture. May have to get help in getting it into this page.

Yes gauge is attached to end of pigtail loop just as you stated. Earlier the gauge was removed & verified the pigtail was clear. Thanks.

briggs

Hi Jamie, Here are the photos of the pig tail loop.

Jamie Hall

Not the most common arrangement — but no reason it shouldn't work fine.

SteamingatMohawk

Especially if the pressuretrol is of the mercury switch vintage.

mattmia2

That 0-30 psig gauge probably isn't very accurate at the .5-2 psig range of the system, a 0-3 psig or 0-5 psig gauge is what you need to compare to a pressuretrol setting.

briggs

Ok Thanks Jamie.

Steamingatmohawk Ok mercury is more sensitave?

mattmia2 Thanks for this. Can you suggest a manufacturer & part # for a 0-3 psi gauge? Thank You All !

SteamingatMohawk

Other HHers can answer the sensitivity question. I don't have any experience upon which to judge.

I think the mercury switch was phased out because of the toxicity of the metal….even though as kids we played around with it on the tabletop in school.

BobC

A mercury buld is just about fail proof but the mechanicals that move it are not. the problem with a mechanical snap switch is they are not really repeatable and are liable to wander around the set point.

If youhave a mercury pressuretrol or vaporstat do not let go of it.

Bob

mattmia2

Here's one, there are others.
https://www.supplyhouse.com/Winters-Instruments-PLP304-2-1-2-PLP-Steel-Low-Pressure-Gauge-1-4-Bottom-NPT-w-Brass-Internals-0-100WC

briggs

Thanks for the help on the mercury vs the snap & the pressure gauge.