Another pressuretrol question

ratherbfishing

I've read through a number of posts related to this but was hoping for more specific answer.

I replaced a pressuretrol that wasn't cutting out (clean pigtail) with a direct replacement (resideo PA404A 1074). I installed it along with a low pressure gauge. It's set at diff =1 cut-in =0.5. It cuts out at ~2.25 and back in (correctly) at 0.5. The gauge setup is temporary just for testing, i'm running the pressuretol directly on the pigtail now.

Should I try to return and get another? Replace with vaporstat (if so, which)? leave alone because it's ok?

thanks

Hap_Hazzard

I'd return it and fix the old one, unless the diaphragm is shot. Then I'd try another new one. You can adjust the cut-in, but if the differential isn't what it says on the switch, the switch is defective. I mean, ±67% isn't a reasonable margin of error.

ethicalpaul

It's about as accurate as they get. I'd spend my efforts trying to minimize the pressure so that the pressuretrol doesn't have to worry about it

SteamingatMohawk

Multiple discussions on HH each winter on this issue.

@ethicalpaul is right.

When I tested my new one, with 0.5 cut in and 1.0 diff, it cut out at 2.6 and in at 0.6. I contacted the manufacturer and was told the unit is operating in spec or+/-1.0psi. No satisfaction at all.

Bottom line is it is not a good choice for low pressure applications.

A general opinion seems to be to use a 0-4 psig vaporstat if you want to spend the money.

EBEBRATT-Ed

I just installed a new one two weeks ago and that's as good as is gets.

PRETTY SAD...HONEYWELL >>>RESIDIO

Listening??????

ratherbfishing

So basically this is the best alternative?
https://www.supplyhouse.com/Honeywell-L408J1017-Vaporstat-Controllers-0-psi-to-4-psi

KC_Jones

I wouldn't bother.

Time and money are better spent elsewhere.

Get everything else on the system as good as it can be and just let it go.

Low pressure should come from proper boiler sizing and proper venting.

How is your venting (especially mains)? Do you know if the boiler is properly sized?

ratherbfishing

Need more main venting. not sure about boiler sizing. But was just figuring since I had to shell out for a functioning pressuretrol maybe i should get one that actually is (working) low pressure. the price difference isn't that much

Jamie Hall

ratherbfishing said:

Need more main venting. not sure about boiler sizing. But was just figuring since I had to shell out for a functioning pressuretrol maybe i should get one that actually is (working) low pressure. the price difference isn't that much

Agreed...

SteamingatMohawk

Since you have a low pressure gauge, what pressure does the system operate at? If the system pressure stays low, the existing cut out is probably good enough.

Save money like @Jamie Hall suggests.

ratherbfishing

The system starts to build pressure after about ~30-35 minutes, 45 minutes to get to 1.5 psi. I'm not sure what the top end of the pressure is (the built in gauge is worthless) because with the LP gauge on, I cut the system before it hits 3 to save the gauge.

Jamie Hall

If you decide to add a 0 to 4 vapourstat, setting it to cut out at 1.5 psi and back in at 0.5 would probably save some fuel. Enough to pay for it? Probably not...

ratherbfishing

Fair, that's a good point. I'm also thinking ~2.5 psi won't do unruly damage to rad/main valves either, right?