Which Pressuretrol do I need?

lbeachmike

My heating contractor serviced my steam boiler and recommended I replace the Pressuretrol due to it being "a bit temperamental". They said it is a p404a. If they replace it, they charge $400 for the part, so I'd like to furnish the part and waive the one-year part warranty.

I see more than one version of the p404a (I see a 1033 and 1025.) How can I determine exactly which one I have, or which is recommended for my boiler? It is very difficult to get behind this boiler to get a photo from the back of the unit.

Boiler is a Burnham:

Model Number: QSIN5SNC-HE2

Product Name: NatGrid Independence

EdTheHeaterMan

The last four numbers are printed on the control case. usually in a purple ink or a sticker. Take the cover off and look for the number.

Those controls are not the most accurate measuring devices. What seems to be the issue? Is the boiler pressure going to high?

EdTheHeaterMan

Look on the sides also.

lbeachmike

It's a rental property. The tenant has not complained at all. The heating contractor was fixing a different issue and simply said it wasn't behaving normally and would result in the unit kicking on and off more frequently. I did not get any clarity on the issue. What is the expected life on these? It is about 11 years old.

Isn't it possible for me to find out which Pressuretrol is needed based on the model number of the boiler?

ethicalpaul

He's got it set a lot higher than I'd like to see it…it won't cut out until 3-5psi at that setting (3 psi according to the setting but maybe 5psi according to how bad this device operates).

Those two models of pressuretrol are additive and subtractive. Either one can be used. The one in your picture is additive because it displays "Cut In" on the front indicator. It's this one which is the only kind of pressuretrol I've ever seen in NJ

I wonder what he means by "unit kicking on and off more frequently".

I don't know the expected life, but my last one lasted longer than my boiler, about 30 years with a good deal of cycling.

lbeachmike

Looks like the previous post answers my question about which part. It looks like it is the 1033 ($141 on Amazon, btw.) I guess the question now is whether or not it really needs replacement.

JUGHNE

Did anyone clean the pigtail under the control?

If it is partially plugged that could throw the operation out of kilter.

Also how is your steam main air venting?

I have some of these controls 40-50 years old and still function as well as they always did……not real well even if brand new.

lbeachmike

The pigtails were not cleaned by this contractor. I guess that is a miss on their part.

EdTheHeaterMan

So you need to get a steam person to look at this. If your guy is not a steam person, then they should not be learning on your dime.

When was the last time you had someone do a complete maintenance on that boiler? Flush out the wet returns and the boiler? Check the pigtail for blockage, test the Low Water Cut Off? The stuff that keeps the boiler from destroying itself.

ethicalpaul

https://forum.heatinghelp.com/discussion/comment/1815657#Comment_1815657

Ouch. His advice to purchase a new pressuretrol is highly suspect

delcrossv

Replacing the pressuretrol is way down the list of things to do regarding boiler maintenance.

Boiler flushed?

Main vents checked/replaced?

Low Water cutoff cleaned/checked?

Pigtail cleaned?

Gauge Glass cleaned?

Heat exchanger cleaned ? ( really necessary for oil burners)

Burners cleaned /serviced?

And, after all that….

Pressure still high? Then check pressuretrol.

Note, for residential heating, that pressuretrol should be set as low as possible 1.5psi cut out, 1psi differential.

EdTheHeaterMan

@delcrossv said "Note, for residential heating, that pressuretrol should be set as low as possible 1.5psi cut out, 1psi differential."

depending on the control you may need to set the cut out @ 1.5 PSI and the differential at 1 PSI Depends on what it says on the control… Cut In or Cut Out.

Some controls are additive.

And some controls are subtractive

delcrossv

I like subtractive so my instructions are for those. For some reason additive ones seem backwards to me.😜

ethicalpaul

I just noticed the subtractive one (of this model) has a different range, that is weird. It goes from 3psi to 15psi. Not for residential!

delcrossv

https://forum.heatinghelp.com/discussion/comment/1815676#Comment_1815676

Yesh, should be this one, I think.

https://www.supplyhouse.com/Resideo-PA404B1023-Pressuretrol

Pumpguy

For the low pressures recommended, wouldn't a vaporstat be a better choice?

A bit more expensive, but usually reported to be a better choice for operation at very low pressures for residential systems, or am I wrong about this?

ethicalpaul

https://forum.heatinghelp.com/discussion/comment/1815725#Comment_1815725

The benefit to a one-pipe system is IMO marginal. The effort should be put into sizing the boiler at replacement time. Then you don't need a pressure control to manage pressure except only rarely

lbeachmike

https://forum.heatinghelp.com/discussion/comment/1815659#Comment_1815659

Thanks - the main finding was a leaky 1 1/4" black pipe on the return, which will be replaced by a different contractor. I will have that contractor check out the pigtails and other items mentioned here as needed.

ethicalpaul

Sounds good, let us know how it goes!