boiler keeps going off/on, off/on....help!

**Doherty Plumbing** · 12-07-2009, 03:53 PM

That thing is OOOOLLLLDDDDD.

Anyway any more info (or pictures of your boiler room) to aid us in helping you solve why your boiler keeps tripping off on it's limit switches.

**Peter Griffin** · 12-07-2009, 04:06 PM

Dem ain't radiators dem is convectors and they are always piped paralel off a monoflow tee system.

**rmelo99** · 12-07-2009, 04:25 PM

Some pics of the boiler room piping would help us confirm your piping setup.

It will also help us to guide you to purge air...could be an air lock in the piping that needs to be purged out of a purge valve in the basement.

Think of the piping as one big loop with a start(supply) and finish(return). The water has to leave the boiler work its way thru the system and back to the boiler. The circulator moves the water. Sometimes the air blockage is big enough the circulator can't push it through. Need to confirm water is making it's way all the way around before you go looking for bad equipment.

One zone, multi zone? Any zone valves?

**TonyV53** · 12-08-2009, 06:25 AM

Yes, the units are 1950 old. I will try to post some pics of the boiler room tonight but it won't be until later.
It's one zone, and I have a zone valve coming off the boiler.
Thanks again,

**jadnashua** · 12-08-2009, 08:17 PM

If there's only one zone, why do you need a zone valve? Do you have an indirect WH?

**TonyV53** · 12-09-2009, 06:32 AM

**Peter Griffin** · 12-09-2009, 10:33 AM

Tony, the problems is one of three things ok maybe 4

1 - the circulator is not working
2 - the aquastat is either not sensing temperature, broken or not properly adjusted
3 - the flow check valve is stuck closed
4 - You have air in the system
5 - the heat anticipator on the thermostat is burned out

However, do yourself a favor and rip that piece of crap out of the house. It's taking the money out of your wallet by the handful. On a good day it might make 75% efficiency and that was 40 years ago when it was brand new. You can probably cut your oil bill about in half with a new boiler and outdoor re-set controls.

**TonyV53** · 12-09-2009, 02:09 PM

I agree, it is a piece of crap, and I wish I could replace it but I don't have the money in my budget this year, and I have no way to fitting it in. It has to last me until next year.

About your 5 possible causes. Please keep in mind I'm a novice, if that when it comes to boilers. This is all new to me.

1 - the circulator:
Heat does get to the convectors and they do get hot, and house does get up to about 58-60 degrees, so I would think the circulator is working.

2 - the aqua stat is either not sensing temperature, broken or not properly adjusted:
I think the aquastat is working because I have it set to 180 hi/150 low.
It reaches about 190 with about 25-30 psi now, and then shuts off and started dripping water again from the safety relief valve.

3 - the flow check valve is stuck closed:
This is something I need to look into and check, but I'm not sure what I'm looking for.or how to do it.

4 - You have air in the system:
Another thing I need to try and check and try to verify. I just don't know how to go about check it or relieving it.

5 - the heat anticipator on the thermostat is burned out:
Very possibly…its and old manual Honeywell, so I wanted to swap it out anyway. I do that this weekend.

Thanks for your help. I really appreciate it. Is there any way you can give some direction on # 3 & 4??

**Peter Griffin** · 12-09-2009, 03:13 PM

Number 3 - That red thing that says B&G on it, yep that think, it's the flow check valve, smack it with a hammer. Yes I said smack it with a hammer. Don't get carried away but give it a good rap or two.

Air needs to be purged at the convectors but if they are getting hot you probably don't have an air problem.

Try jacking the thermostat all the way up and see if it keeps running for a longer period of time. If it does, it's a bad thermostat. You could also bug the tt wires together at the primary control to bypass the thermostat and again, if it keeps on running it's the thermostat.

**rmelo99** · 12-09-2009, 05:19 PM

I've seen worse....but it is old.

I had a similar b&g check valve on one of my old systems. I cant see the top but mine had a lever of some sorts that you can turn counter clockwise to

open the check valve...not a permanent solution but if that is your problem it will open the valve.

As to some convectors getting hot...heat rises so sometimes even if the circulator is shot the hot water will push cold water out of the rads and get them hot.

OLD gravity systems didn't have circulators and they worked.

Twisting the thermostat wires together is an easy fix to rule that out...I would not do it at the thermostat but rather short it at the boiler in case there is a problem with the wiring up to the actual thermostat on the wall.

Don't forget about Craigslist for a used boiler.
You are in CT so there are many people that sell boilers when they expand their houses or knockdown their old houses. I see them on CL all the time for cheap. I always look for gas ones but there are plenty of oil ones out there too. Sometimes free sometimes only a few hundred bucks!

**TonyV53** · 12-10-2009, 09:33 AM

Awesome info guys. I will try the recommended troubleshooting and post back with the outcome.
I never even thought of trying CL for boilers. I tried finding replacement convectors there but never thought to look for boilers, thanks!

Thanks again guys. So glad I found this forum.

**Doherty Plumbing** · 12-10-2009, 08:35 PM

Originally Posted by TonyV53

Awesome info guys. I will try the recommended troubleshooting and post back with the outcome.
I never even thought of trying CL for boilers. I tried finding replacement convectors there but never thought to look for boilers, thanks!

Thanks again guys. So glad I found this forum.

Your gas valve could also be failing. You need to also check to see if you have voltage across the gas valve when it fails. If you do you know the gas valve needs to be replaced. If power is cut to the gas valve before it fails you know that there is a limit or safety that has tripped.

**rmelo99** · 12-12-2009, 04:07 PM

Pretty sure it isn't the gas valve,seeing as his unit is an oil burner based boiler!

Saw this on CL and thought of you.
http://newhaven.craigslist.org/for/1503547502.html

**Doherty Plumbing** · 12-12-2009, 05:02 PM

Originally Posted by rmelo99

Pretty sure it isn't the gas valve,seeing as his unit is an oil burner based boiler!

Saw this on CL and thought of you.
http://newhaven.craigslist.org/for/1503547502.html

ROFL I forgot that small little detail! oops!

**MAoilTech** · 12-15-2009, 01:51 PM

I'm a Master Oil Tech I'm Reading whats going on just adding my 2 cents

your aqua stat setting to high (This time got up to about 205 w/15 psi.) @ 30 psi and over your relief valve will let go
212 ur making steam if you have it @ 205 or 200 when your boiler hits that mark it will shut off but the temp will still go higher this will cuz banging in pipes pumps will go bad valve will leak in time normal range 160 low and 180 high def# 20 ur psi range 17-22 psi for water this will also go up when water is heated.

Replace you aqua-stat it sounds to me it not working if you can get a Hydro-stat it can read boiler water temp as well. also if you do not get ur hot water from you boiler such as Coil take the low side drop to lowest setting 120

Install a Purge set up above circ pump 3/4 x 3/4 x 1/2 c x c x f tee cant realy tell on ur pic if its 3/4 or 1 in but you get the idea
1/2 boiler drain and 3/4 ball valve. this will help with air in lines for now and later.

350.00 buck's for a Cad cell? highway Robbery

Also i didnt see a expansion tank in your pic's if you dont have one install one.
http://www.hydrolevel.com/pages/new.html