ONE PIPE STEAM PROBLEM JOB

Troubled Tech

I have to set the pressure cut in at 2 and the out at 3.5 to get to come on. Will run till gets hot, about an hour then will lock out. Till pressure is set up again.
Have Mcdonald low cut off. ps804-24 honeywell pressure switch pa404a1033. and mcdonal miller electric water feed.
Boiler is Burham IN12NI Serial 64062324
One pipe with 2inch headers 3inch main and hartford loop is present.
New job to me very old piping. Anyone with a thought.
Thanks, Troubled Tech.

[Deleted User]

Steam problem

Sounds like the syphon piping under the PA404A is plugged.
I would check that first.

If that is the problem, don't forget to set the pressure back DOWN.

Good luck.

John@Reliable

One pipe steam

Sounds like you need to remove pigtail and check piping for blockage. I would try to clean all piping but the pigtail(replace with a brass one). Also once clean I would consider replacing the pressuretrol to avoid a call-back if over 10 years old. Hope this helps John@Reliable

Dale

Changing the pigtail

This can't hurt an may be why the control isn't seeing the hopefully lower pressure as the boiler quits making steam. You can easily test this by opening the relief or some other steam vent and seeing if the control closes. Remember the control switch should have continuity or be closed at 0 pressure. If you unscerw it from the pigtail it should reclose.

Troubled Tech

I have so far done

I have changed the pressure switch and cleaned the pig tail. and still have the same problem any more input would be greatly appriciated. Thanks guys.
Troubled Tech

Unknown

Are you saying

If you set the cut in lower than 2 , it doesnt come on at all ? We had a bad batch of PA404As a few years back , cut in at 1 1/2 - differential at 1 , where the new boiler would cycle once , go off , and not come back on . We had to set the cut in to 2 1/2 to get it to work at all .

Troubled Tech

Yes that is excatly what Im saying.

Unknown

Where on the boiler

is the pressuretrol located ? The higher on the boiler , the better . The only other thing I can suggest is to change the pressuretrol to one with a mercury switch - dont know the model number - , or a vaporstat . Both work more accurately than the PA404 . The vaporstat can be cranked down to ounces of pressure .

Unknown

vaporstat

the 0 to 16 ounce vaporstat is Honeywell# L 408A1132.

Noel

Troubled Tech

Thanks

I will try the vapor stat. with brass pigtail.
Thanks.
Chris

Troubled Tech

6 inches or so above water line

terry_6

I would be careful with the Vaporstat 0-16 oz. as some one pipe systems don't like them. I put one on here (residential,246k btu - 40k for altitude) but the system seems to like running at the max, 16 oz. until it settles into each cycle which then short cycles causing problems. I'm switching to the L408b1149 which works 0-4 psi. That way it won't short cycle even though most of the time the system runs at 10 oz.

Troubled Tech

Thanks for input

The boiler is 340,000 btu input so maybe the honeywell l408b will work best.

terry_6

The L408B comes in 2 flavors. The 1131 is 0-16oz. and the 1149 is 0-4 psi.

k.c.jones

radiator pitch

What is a good pitch on a one pipe radiator ?