bad pressuretrol, bad pressure gauge, or something else?

rca

Hi all,



The boiler for my apartment has been acting up for the past two months and my landlord and I are trying to figure out how best to proceed. Our guess is that it's some combination of a bad pressuretrol and/or a bad pressure gauge, but we wonder if maybe it's something else entirely that's the root of the problems...



It's a 1-pipe steam system. The boiler is a burnham independence IN4 gas boiler that's about 5 years old. The near boiler piping is correct. The pressuretrol is set to cut-in at .5 psi and cut-out at 1.5psi. The pipes and radiators are pitched correctly and there are new varivalves on the radiators. The radiators are probably 75 years old. The pressure

gauge on the boiler never goes below 2psi - up until recently we didn't think it moved at all.



The problems started with one of the radiators developing a leak at one of the seams between the columns, and around the same time another radiator developed a leak from the packing nut on the valve. We used JB weld on the radiator (to buy some time to find a replacement) and replaced the graphite string in the packing nut. A couple of weeks later the radiator which had the leak from the packing nut developed its own leak at one of the seams. More JB weld, and things were OK again for the next couple of weeks. At the time we thought it was coincidence that the two radiators both sprung leaks.



My landlord then added a silicate solution to both our boiler and the boiler for the first floor unit (apparently it's supposed to seal up any leaks in the system?). Over the course of the next week both of us had horrible water hammer. While the water hammer was occurring one night I went to the basement and noticed that the pressure gauge on the boiler was reading about 9 psi and it rose to 9-1/2 while I watched - the first time I had ever seen it read something other than 2 psi. Also, there was a very small wet patch on the floor near the boiler which based on its location could have come from the pressure relief valve or from a leak from the main sewage pipe (not that we're aware of any such leak).



The next day we had a tech from the local heating company come down to check things out. He determined that the wet return line was clogged and that was causing the water hammer. He also checked the pigtail that the pressuretrol is mounted on and determined it was OK because he could blow through it easily. He suggested the pressure gauge was not to be trusted and attributed the wet patch to the sewer pipe.



So...the return got snaked out and flushed (it was clogged), and the boiler was drained and refilled a couple of times. Things were OK again for the past two weeks until today. The second radiator began leaking again from the same seam that we epoxied, and when I checked the boiler the water level was OK but the pressure gauge was reading about 10psi.



My landlord and I are trying to figure out whether we need to call up the heating company again or whether we can do some of the work ourselves, possibly replacing the pressuretrol, for example. (the service contract just gives a discount, but it's not free). Our thinking is that the pressuretrol is flaky - sometimes working correctly and other times not, because that would explain the stretches when the system is working OK as well as why the radiators keep springing leaks, the wet patch on the floor, and the high readings on the pressure gauge. But is there some underlying cause that could be leading the pressuretrol to malfunction?



What does everyone think?



cheers,

-Bob

nicholas bonham-carter

wild pressure

get a good low-pressure gauge [gaugestore.com  0-3 psi]], you can trust, on the pressuretrol pigtail. then you can see what's happening. when you replace the pressuretrol, assuming that it has been ruined by the boiler solution, get a 16 ounce vaporstat, so your landlord can start saving some money right away. make sure all the stop leak has been flushed out. peerless recommend using arm&hammer washing soda, and burnham probably have some suggestions too.

both the gauge and vaporstat can be replaced by yourselves. just dry assemble the pipe fittings with them before you remove the old. that way you can see how things fit while still maintaining heat. use long enough verticals to put the antler well above the  top of section level. you will be somewhat restricted by the wire length going to the vaporstat as far as its placement.

this over-pressure has probably ruined the main vents, so order some big gorton #2's. remember you still have a month's gas to burn less of!--nbc

TomM

gauge

+1 on adding an accessory gauge first.

rca

will 10 psi damage the low pressure gauge?

If the pressuretrol is malfunctioning we don't think the boiler solution is what damaged it - at this point we suspect it was malfunctioning for the month before the silicate solution was added and causing the leaks in the radiators, but we just didn't happen to check the boiler at a time when the pressure was high.



I've seen other posts recommending a 0-3psi wika gauge. If the boiler is actually getting up to 10 psi will that damage that type of a low pressure gauge? If the pressure problems might ruin a 0-3psi gauge I think we'd put on the new 0-30 and then put on a 0-3 when the new vaporstat gets put on (if the pressuretrol is indeed malfunctioning). If we don't need to worry about the 0-3 psi gauge getting damaged then I think we'd actually start with that (and maybe not bother with a new 0-30 since it's not terribly useful in ordinary circumstances).



Could you explain what do you mean by "the top of section level"?



Also, there haven't been any main vents on the system for a while (the details are in a post I made a few months back) - the system is relatively small (main is about 20ft long, and serves 6 radiators), so we wanted to see if the venting from the varivalves would be sufficient.



P.S. Burnham's installation manual says: "A local qualified water treatment chemical specialist is a suggested source for recommendations regarding appropriate chemical compounds and concentrations which are compatible with local environmental regulations."

Unknown

What does the gage read when the boiler is cold

You state that you have seen the gauge reading in the 9-10 PSI range a few times that coincided with leaks in different areas. When the boiler is off and reasonably col does the gauge read 0 PSI?



If it does get down to zero when cool, I would be very leery of the pressuretrol, they can get flaky for no apparent reason.  I would install a vaporstat and a new low pressure gauge so you can monitor things. If money is tight you could just replace the pressurertrol but in the long run, a vaporstat is the way to go. Start with a cutout of 1.5 PSI and a differential of 1 PSI, and work your way down from there. It would be best to flush out any added chemicals before adding these, just make sure you have the boiler fire after doing everything to drive off the oxe3gen in the water.



When I modified my boiler it cost me about $200 to do the work myself and I've saved that amount on fuel. The pipe fittings are all 1/4" and can be had at a good hardware or lowes/homedepot. See the attached picture

rca

gauge reads 2psi cold

When the system is completely off the gauge reads 2psi. I've never seen it read anything lower than that, and until a couple weeks ago I had never seen it read anything more than that. At this point I've seen it read 9-10 psi twice, once when there was water hammer (but none of the radiators were leaking) and again yesterday while one of the radiators was leaking.



Could you describe the process of firing the boiler to drive off the oxygen in more detail?



thanks,

-Bob

Unknown

To get rid of excess oxygen- boil the Water!

Anytime you add fresh water to a boiler you need to bring it to the boil (make steam) as this drives off the dissolved oxygen which can be very corrosive to your boiler.

While having an automatic water feeder can be an big advantage, there is a downside in that if your boiler develops a slow leak, the feeder will keep adding fresh water and this, in time, corrodes your boiler and leads to a greatly shortened boiler life. That's why it is suggested that if you use an automatic feeder, you use a Hydrolevel VXT as it keeps a digital count of the amount of water added.

- Rod

Unknown

re: 2 PSI cold

That pressure gauge is shot if it reads 2psi when the boiler is not steaming and is probably not reliable. If you replace a 30 psi guage you need an internal syphon 0-30psi gauge.



If you look at the picture on my original post you can see my 0-30psi gauge behind a romex cable. I added the 3 PSI gauge when i had to replace my pressuretrol for the second time in 12 years; thats why I decided to spring for a vaporstat. Note that my vaporstat and the new 3 PSI guage are on a syphon loop to isolate them from live steam. Even a working 0-30 PSI gauge will not tell you much about whats going on in a steam system operating at 1.5 PSI or less.



A replacement pressuretrol will set you back about $80-90 while a vaporstat will cost twice that (three times more if your not careful). Replacing a gauge or pressure control takes about 15 minutes, just make sure the system is cool and power is switched off. Also make a little diagram so your confident about the wiring.



good luck,