Pressuretrol Question

adasilva

New to the forum and new to steam heating as I just bought my house this year. I have been reading about the lower the pressure the better the steam heating works. So I set my pressure to 0.5 as suggested and the deadband (differential) at 1 and the boiler failed to turn on when the tstat called for heat. I have a New Yorker Boiler that was installed in 06 and it is fired with natural gas. Single pipe system 2" main w/1.25" branch piping to the rads. I am perplexed as to why it did not turn on due to the lower setting? It was set at 2PSI and when I returned it to that setting it fired as usual. There is a label that shows the boiler as a 3 LB boiler? Any info would be awesome to clear up my confusion on this matter!

mikeg2015

Gauge could be dirty.

Pigtail may be dirty.

JUGHNE

Sometimes when these are adjusted to the bottom of the range the linkage comes apart. Look inside the control you will see the end of the screw loose, perhaps.

Fred

Do you have a 0-3 PSI gauge on the system so you can see what the pressure really is? A picture of the Pressuretol would help also. Is it a Honeywell 404? If so, I would say it didn't come back on because the pigtail is clogged and the Pressuretrol side of that loop is holding pressure above the .5 PSI, causing the boiler to think it's not at Cut-In pressure. I doubt that the linkage dropped off since it did fire when you returned the setting to 2 PSI.

adasilva

OK to answer the questions...
Mikeg2015; I agree that the gauge could be dirty as the gent I bought from claimed to have the boiler serviced biannually! Is this something that I can do without draining the boiler?

JUGHNE; This is not the issue as it did fire back up (Like Fred mentioned) when I returned it to the 2PSI setting and I did hear a click as I adjusted the screw.

Fred; The only gauge that I have is the one pictured 0-30 PSI, seems to sit at 3 when idle and 5 when running but I have not actually sat long enough to watch it. Also, it is a Honeywell 404A I will include pictures. The pigtail cleaning seems to be a simple job to do. I

Big Ed_4

The L404 is way out of the range needed .. Yes normally that is what is used for it's price .An Vaporstat is an better choice , the range is set in ounces ..

First as mentioned , pull the pigtail make sure it's clean . Use an wire and water to clean and flush it out if plugged . Adjust the setting to it's lowest .. I check when there is no pressure on system. lightly use a screw driver to lift lever in control .. You should heard the cut out click and when release hear the cut out click .. Then slight increase on pressure for safety ..

adasilva

Big Ed I will do this when time allows probably sometime during the week and post what I find and end result

Gordo

@adasilva : I would say that your 30 psi gauge is at least partly clogged and is failing and for the most part merely acting as a 1/4 npt plug for that hole. It should be replaced as it is required by Code. It could also be re-located, but we'll get to that later.

@Big Ed : makes a good point that your pigtail is most likely clogged. It is steel and it should be replaced with a brass one anyway. But if you can't get it unclogged now and you have no heat NOW, lets us know. Clogged (or mostly clogged) pigtails can make pressuretrols do seemingly strange things and should be a yearly checklist item.

When you get a new brass pigtail, set it up with a tee, nipples and a 90 so you can add a new 30 psi gauge. That way, you can remove the gauge every year and blow thru the pigtail to test it.

As @Fred has advised, getting a 3 psi gauge is a great way to see more accurately the pressure your system is actually operating at. You can replace the 30 psi and keep it where it is, but you should get one with an "internal siphon", and put your new, more useful, 3 psi gauge on your new 1/4 tee tree.

Your pressuretrol could also be off calibration, but that's another story.

adasilva

Gordo; I can do all that for the pigtail and probably obtain the tools to calibrate the pressuretrol myself. I'll check the pigtail this week and if I can get a brass one to replace I'll set it up as you discribed and go from there !

adasilva

Gents,
I have a new pigtail coming tomorrow along with the tee, elbow and close nipple and gauge. 0-30 for now and I will obtain the 0-5 at a later date.
Anyway in the meantime I have taken the old one out and cleaned all the material that was blocking it and reassembled it. Set the cut in to 0.5PSI and left the differential @1 and fired the boiler up. There really isn't any difference that I can tell as it seemed to run for the normal time frame about 20 min and did not shut down at all till the temp was satisfied (via the tstat). Almost like the pressuretrol wasn't there at all? I know you (Gordo) said that it might be out of cal, this may be my next step. I did move the linkage and I do hear the switch operate when it is moved (I did this when the system was at idle after I cleaned the pigtail) is this to be done while the boiler is running? If all was working as it should am I to assume that it should turn the fuel off when it reaches 0.5 PSI by the pressuretrol or am I wrong?

One silly question, do I add water to the pigtail?

Fred

@adasilva Yes, You are wrong. What is happening is exactly what you want to happen. The Pressuretrol is really a safety control. The boiler should run as long as it needs to satisfy the Thermostat. The Thermostat is the temperature control.
The Pressuretrol should not cut the burner at .5 PSI. The .05 is the Cut-in pressure. Whenever the pressure falls to or below that, it will allow the thermostat to call for heat and it will allow the burner to fire.
The "1" setting, inside the Pressuretrol is the differential, meaning, on an additive Pressuretrol (which you have) that the Cut-in Pressure plus the Differential .5 + 1 = 1.5PSI is the pressure that the Pressuretrol should turn the burner off to control system pressure. If you are fortunate, your boiler will never or only rarely (maybe during a deep set-back) reach the pressure that the Pressuretrol would shut the boiler down. At all other times, it is as it it weren't even there! You should put a little water in the pigtail but if you forget to, it will fill soon from condensate.

adasilva

Awesome news Fred! At least I'm in the right track. Now to get me a 0 to 3 psi gauge!

adasilva

0 to 5 psi gauge and the boiler rarely sees more than 3/4 psi. Is this good or bad? All the rads heat up and the pipes are quiet. New main vent installed as well. Seems ok to me, thoughts.

Fred

That's about 12 ounces. That is fine.