Pressuretrol not calibrated, should I worry?

Al Letellier

How are you testing the accuracy of this control? Are you using the gauge on the boiler? These gauges are notoriously inaccurate and less that trustworthy after awhile. Try another gauge first, they're cheaper.

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superMARKet

It cuts in and out too high!

Dear wallies,

I've got a one-pipe steam system with a pressuretrol (Honeywell PA404A) that's out of calibration. Right now, it's set to the minimum cut-in of 0.5psig and the minimum differential of 1psig. Unfortunately, the actual cut-in is 2.2psig and cut-out is 3.4psig.

Is this worth worrying about? I'm concerned that I'm burning money on oil at this pressure, and that the system might heat more efficiently and evenly with a properly-calibrated pressure control. I'm also wondering if the overfiring might be the cause of the end-of-cycle water hammer I sometimes get.

Should I get the pressuretrol replaced or is it not worth it?

Mark

superMARKet

I'm using the boiler gauge, which is less than a year old.

Mad Dog

Get yourself a good USA made Guage that reads in ounces

(They are not aesy to come by, Try Weksler or US Guage) And getr your self the Honeywell mercury tpe Pressuretrol - its a lot more sensitive and accurate. Get that pigtail nice and high out of the surging boiler water. Mad Dog

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David Efflandt

gauge on 2 yr old boiler blocked & faulty

When I bought a home a year ago, the gauge on the then 2 yr old Bryant boiler was reading high, so at first I thought 10 meant 1 psi and 15 meant 1.5 psi. Somebody had set pressuretrol at maximum (9 psi cutout?) due to vent damper that stuck closed when hot (discovered after reducing pressuretrol to minumum settings on oversize boiler). Vent damper was replaced.

Gauge still read high when removed. Different gauge revealed that the extended snubber was blocked, so all the gauge was reading was trapped heated air pressure in the snubber. Once that was fixed and metal pressure/vacuum gauge installed, I found that the pressuretrol was working properly (0.5-1.5). Many pressure gauges (including original) don't even go below 2 psi.

Firedragon_4

That control has

the accuracy of a bean blower in the dark, FACT! Dump the PA404, put on a real control, L404, and I wouldn't worry what the gauge tells me. In residential most fail after a week and the rest 99% are wrong anyway.

Unknown

And protect the gauge

with a pigtail also . I used to nstall the gauge right into the boiler and we were lucky if they lasted a season .

superMARKet

I think the existing gauge is close enough

It's a new gauge on a dedicated pigtail, level with the operating and manual-reset pressuretrols. I believe the gauge is accurate enough, because it read 5psig when the manual reset was set at 5 and opened.

Once I start raising any pressure at all, it takes about 20 minutes to get up to the point where the operating pressuretrol starts cycling it.

Humor me for a sec': assuming my gauge is OK, what am I losing by having the burner cycle in the 2-3psig range rather than something lower?

Mark

bottomheater_2

l404 not cranking too low

in reference to the L404 suggestion: is that the control with the mercury switch and the clear cover? nice control but the scales don't read below 2lb and i just saw one set lower than the scale that would cut out but not in. real control indeed but not if you want 1-1/2 lbs.

Bill NTSG

Pressuretrol

The point is, the pressuretrol is the high limit for a steam boiler. It is an operating control, but is also a safety control. And I am somewhat concerned about your safety.

Make sure your pigtail syphon is not plugged. Take it off and blow through it to make sure. You should never have to build pressure to heat your house. It sounds like you have venting issues.

Please check out Dan's Lost Art of steam heating. Check out this link on this site about pressure.

http://www.heatinghelp.com/newsletter.cfm?Id=54

copy and paste

superMARKet

Bill, thanks for the notes and the concern for safety. The separate manual reset cut-out control is working properly. My only concern is the "low" high limit switch, which is out of whack.

None of the vents leak, and all of the radiators get hot, so I assume the vents are closing and opening properly. What other "venting issues" might I have?

All of the stuff I've read so far, including the great stuff Dan's got, says why it's good to run with very low pressures. I guess what I'm looking for is something that says how bad it is to run the pressures my control is forcing me to use now. Will it hit me in the wallet, will I lose karma points, will I be spending eternity tending larger flames, etc.?

Thanks again,
Mark

Bill NTSG

It Will

Bite you in the wallet. There is an article somewhere on this site about air vents. If I locate it I will post it.

Air vents open and close during cycles. This lets the air out and the steam in and holds the steam in until you get all of the heat from it. These vents have what is called a drop-away pressure of around 3 psi. This means the vent can't open against pressure to let more steam in.

So that means you will build more pressure to try to 'force' more heat into the radiator. It won't work, you will just burn more fuel.

Usually pressure on the gauge tells me the venting [not always] is inadequate. Like too small, partially or completely blocked or non-existing end of main vents etc. I have not seen your system so of course this is all speculation. You'll get it squared away, good luck.

superMARKet

Bill, thanks for the explanation, that's EXACTLY what I was looking for!

Mark

Firedragon_4

There are several models of the

L404 including one that reads in ounces.

Check this out: http://hbctechlit.honeywell.com/Default.cfm?CFID=1098265&CFTOKEN=55379639