steam boiler problem--pressuretrol?

Nick_33

Thanks for the quick response.

The plumber indicated he had cleaned it out when he flushed the system a couple of months ago and there is no way it would clog up again that quickly. Plus, wouldn't he have seen if it was clogged when he replaced the pressuretrol?

Nick

Nick_33

HELP!! -- steam boiler problems--pressuretrol?

HI guys:

I've been having some problems with my steam furnace and came across this site and hope someone can be of help since my plumber appears to be stumped. We recently had some home renovation done which included some new piping for radiators and the addition of 3 new raidiators. Shortly after we started to heat the house a couple of months ago, we had problems with the furnace surging and shutting off. very little heat was coming through the radiators. Called the plumber who did the install and they thought that some of the oil from the new piping and radiators had made its way into the furnace and was preventing steam from forming. They flushed the furnace and poured in some green liquid (sorry I'm drawing a blank on the name) which was supposed to break down the oil and other sludge. The system began to heat properly.

Over this past weekend, the furnace stopped working. I attempted to drain some of the water out to see if it was dirty, and nothing originally came out of the drain. I then tapped on the valve and initially some dirty water came out followed by clear. I refilled the water level but nothing happened. In looking around, I bumped against the pigtail below the pressuretrol and the system fired. I also noticed that the screw for the cut-in control had come loose and was not attached to anything. It would heat up to the set temperature but would not refire again without the pigtail being gently tapped. Plumber came back on monday and indicated the problem was the pressuretrol which had fallen apart inside. He rebuilt it and fired up the system. Again, the same thing happened (of course after he left)--the system would fire initially and heat to the set temperature, but as the temperature would drop, it would not refire without tapping the pigtail. Plumber came back yesterday and replaced the pressuretrol. This has not fixed the problem as the system still fires intially but does not refire without tapping the pigtail.

Does anyone have any ideas as to what the problem might be? I am afraid the easy out for the plumber is to simply state I need a new boiler. But it seems to work fine once it gets fired. Any and all help would be appreciated as we are cold and slowly going broke.

Thanks,

Nick

Steamhead (in transit)

Sounds like the pigtail is plugging up

if it's brass, flush it out. If it's steel, replace it with a brass one.

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Nick_33

My wife confirmed that when he installed the new pressuretrol yesterday, the plumber took the pigtail off and found it not to be plugged.

Steamhead (in transit)

Then

the new control is bad. This happens sometimes on Pressuretrols. Spend the extra money and get a Vaporstat- Honeywell model L408J1009. It is also much more accurate at the low pressures- 1 pound or less- you should be running at.

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JohnG_3

LWCO Bad?

Is it possible that the low water cutoff is not working properly?

I am just a homeowner starting to learn about my steam heating system, but the wiring diagram for my boiler shows that the LWCO and Pressuretrol switches are in series. Therefore, both switches must be "made" in order for the boiler to fire.

Steamhead (in transit)

Anything's possible

but I'll bet it's the Pressuretrol- that's what's connected to the pigtail he has to tap to restart the boiler.

"Steamhead"

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BRIANJ

Pressurtrol

If it works when you tap the pigtail it may be because you have a loose wire on the boiler controls and whe4n you tap it, it makes the circuit. Look for loose connections.

My $0.02.

Nick_33

OK--so my wife comes home yesterday and the house is heating so she assumes the plumber has been there and done something. 10 minutes later the plumber knocks on the door, he had not been there yet. House warms up, we go to bed and wake up around 3 am with the house about 66 and the stat set at 70--not firing once again. Plumber thinks it is the sensor for the low water cut-off and is likely going to replace that next--although he advises it is an expensive part. Can anyone advise how expensive this part might be? Is there anything else we should try before replacing the LWCO valve. This is starting to look like a 3 stooges episode.

thanks again to all for the help.

tim smith

Regarding not firing up

You need someone with a test meter. Check switches for being open or closed before tapping on things and you will find what is wrong! This guessing business does not work. If it is the pressuretrol, make sure again than inlet port to pigtail is not plugged and pig tail has been rodded out. Also is pressuretrol set at lowest setting, you may have taken all tension off spring which will cause hanging up of new switch, this is then not a bad switch but a bad setting for this pressuretrol. Tim
One last thing, it could be that burner is locking out on flame failure and when you tap pressuretrol, you are resetting lockout control by disengaging and engaging power to control. Just a thought but use a test meter and test.

Chas_2

Nick, just a homeowner here, but for the most part folks aren't going to get into cost discussions here. Just too many variables, plus the focus here is problem solving and the like, not costing.
Bruhl

Nick_33

cost issue

Thanks Bruhl:

I was not raising the cost issue to try and shop around for a cheaper price or to nickel and dime the plumber. It's just that when a plumber says something is going to be expensive and does not elaborate, we obviously got a little nervous and are just trying to brace ourselves for what it might be.

JohnG_3

LWCO vs. Pressuretrol

I agree with Tim, you need a good diagnosis before you start replacing parts willy-nilly.

Using a test meter on a live circuit can be problematic though. Another method would be to take the cover off the Pressuretrol, wait for the failure to occur, then use a short piece of wire to short-circuit the two contacts of the Pressuretrol switch. If the boiler fires, then your Pressuretrol, inlet port, pigtail, etc. is the problem. If the boiler still does not fire, then you need to look elsewhere, including but not limited to the LWCO. A previous post mentioned the possibly of loose connections on the wiring, which you should also check out.

Shorting the Pressuretrol switch after the failure occurs might inadvertently duplicate the pigtail tapping that you have indicated gets the boiler firing again. So you might want to prewire a toggle switch across the Pressuretrol contacts and make the wires long enough so that you can flip the toggle switch without physically disturbing the Pressuretrol/pigtail. Leave the switch off. When the failure occurs, flip the switch and see what happens.

tim smith

Meter w/ power on the best way

Best way to test any switch is w/ power applied and look for no voltage if switch is closed and voltage present when switch open. This is testing acrossed terminals of switch with volt meter. Tim