Weil-McLain GV-4 Overheating

Cruisinfanatic

Intermittent overheating as high as 250 and lots of gurgling and hissing

I replaced the limit switch and set lower to 160 but still intermittently goes higher (220) with flame off











Finally got video and audio of the thing doing what it does



Not great, but you'll be able to hear (turn your sound up) and see temp



<a href="http://www.youtube.com/watch?v=l3adlVi9pP0">http://www.youtube.com/watch?v=l3adlVi9pP0</a>



Hope someone has seen this and can help





Lights top to bottom are



Flame



Pressure Switch



Limit



Circulator



Power







Temp gauge



12 o'clock is 160



1 o'clock is 190



2 o'clock is 220



3 o'clock is 250







At 1:20 flame starts and temp goes up



at 3:00 hits 160



at 3:30 starts making gurgling sounds near rear where relief valve and circulator are



at 3:45, 175-180 flame goes off - still gurgling



at 4:00 hissing sound is from the vent - pressure is 20



at 6:15 temp hits 220 even though circulator is still running



at 8:20 circ goes off , still 220



at 16:00 circ comes back on , now 225-230



at 17:00 temp starts back down



at 19:00 fan kicks on - temp is 160



Gas and flame and operates and turns off normally

icesailor

GV-4:

What series is the boiler. Look on the rating plate. Does it have two circulators under the cover or just one? Is there a large black fitting under the cover on the top with a plug in it? Is it a Series 1 or Series 2? Is it piped correctly according to the manufacturers installation instructions? Many were not. If it has two circulators, one may not be working.

Cruisinfanatic

overheating

It is a series 1 with 1 circulator

unclejohn

Thats

An old one. Probably a stuck bypass valve. But did you find out why the pump stopped?

Cruisinfanatic

Over heating

pump didn't stop. I have a  mixing valve

icesailor

Series 1 Gold:

You have your work cut out for yourself. That black fitting inside and at the top has a big cap. There is a thermostatic element inside that has failed and can not be replaced. Weil-McLain has a fix for it and it works. But you have to get the top off. It takes a big socket like 1 1/2", a big bar, and a way to back it up. Where I used to work, there were MANY GV Gold's sold and in operation. Weil-McLain has a tech bulletin on how to fix it. You need to get the cap off and it has to go back in. You remove the thermostatic element and you need one of either two copper caps that you drive into the hole where the water is by-passing.

I never personally did one but had a few customers that had the problem and had to repair them.

Here's a PDF from Weil-McLain on discontinued boilers. Look on page 7. It is the thermostat and is obsolete. It fits Series 1 and Series 2. They usually stick so that they bypass the boiler and you can't get enough hot water.

I never saw what they used to get the plug off but I think that they took whatever 8 Point socket and welded it to a piece pipe so you could put a pipe wrench on it. Unless you have access to an old farmer who has an old set of 8 point sockets. Old farm equipment was mostly square beaded nuts and bolts. Hence, the need for an 8 point.



If you are serious about fixing it, I can get more information for you. Let me know here.

Cruisinfanatic

overheating

A few years ago I had a problem where I couldn't get heat. Baseboard pipes wouldn't get hot enough to heat. The repair guy did this fix. Took the top off and tapped the 1/2 copper cap in the pipe.

This could be the same problem you think? Maybe the cap came loose?

But now I don't have the same problem of no heat to baseboards



Appreciate your help, Mike

unclejohn

Your post

Says 8:20 circ stops 16:00 circ comes back on.

Cruisinfanatic

circulator

I meant that it (circulator) went off because the system wasn't calling for heat

icesailor

New "Brain"?

Has the "Brain" been upgraded? Someone else may be able to tell you the model numbers but it can act like this if the brain is bad. The new one is an upgrade that doesn't require any re-wiring. I did one on a Series 2 about a year ago that had stumped the gas guy. It did similar things. If the circulator doesn't come on, that boiler will heat up and flash to steam quickly. Even if the brain has been replaced, it can still be a bad brain.

Cruisinfanatic

brain

Was replace a couple yrs ago. Reason was  because boiler would not restart every once in awhile (2-3 times a yr. You'd have to shut off power and then it would be ok till next time.

I could swap back to the old one and see I guess

icesailor

Old brain:

Don't do that. That's what the old brains did. They wouldn't start and if you reset the power, they would run.



The "new" brain is different than the old one though?

It sounds like the circulator isn't always starting. Just because the motor is humming, doesn't bean the impellor is turning or even there.

In my experience.

Cruisinfanatic

heat

But still doesn't explain why the temp goes from 170-220 with no flame whether circulator is running or not?

Paul48

I'll

state the obvious. For whatever reason, your hi-limit is not sensing the temperature of the boiler accurately. Is the sensor bulb in contact with the well? I'm not familiar with that boiler, and some of the others can weigh in.....Is it possible there is air trapped in the boiler?

Cruisinfanatic

Temp

The limit switch turns the burner off just fine. Temp keeps rising sometimes anyway

Paul48

OK

It turns off the burner at the same as the setting?

Cruisinfanatic

video

You can see in the video that it turns on about 155 and shuts off by 170

Paul48

Sorry

For me, the video was not clear enough to see the gauge. Is the hi-limit in the boiler, or on the supply pipe?

Cruisinfanatic

guage

limit is in boiler and works fine



as listed in first post,



Temp gauge

12 o'clock is 160

1 o'clock is 190

2 o'clock is 220

3 o'clock is 250

Paul48

icesailor

called it. The circulator may be running, but not moving enough water. When the boiler fires, the surfaces in that heat exchanger get much hotter than your hi-limit setting. They have to, in order to heat the water as it flows across them.

Cruisinfanatic

circulator

Problem  starts around the time the temp gets high enough for the flame to shut down. If the is no call for heat, the circulator wont run. Correct?

icesailor

Starting Circulators:

The Circulator should start at the time the thermostat calls or a zone valve opens and should be running when the burner starts. And runs until the boiler blows up, runs out of fuel or the thermostat is satisfied or all zone valves close. The circulator on that boiler should NEVER stop until the run call is satisfied. If at any time, the circulator stops and the burner is firing on THAT boiler, something is wrong. Either a loose connection to the circulator or a bad brain. The brain controls the circulator. You need a low amp Amp Clamp. A digital one is nicer. Clamp the hot circulator wire, usually the black one. It should give you a low reading with a 007 circulator. If the burner is running and the circulator stops, but still shows amperage, bad connection or bad circulator. If however, the amperage goes to zero and the burner is still running, the brain is taking a temporary dirt nap. Put it to bed permanently.

You can always try the old third world computer repairman trick. Pull out all the terminals on the brain, rocking them back and forth as you do it. Repeat it when you put it back together. I spray a spot of WD-40, CRC or electrical contact cleaner myself, but some might disagree with than. It should help any connections that are acting like warp switches and opening and closing in an arbitrary and capricious manner. If that doesn't fix it, find reasons it isn't the brain.

icesailor

Brains:

I just looked at your YouTube Video.

You said that the Brain/Module has been replaced. When was that? Was it replaced recently with a used Module?

If the Module doesn't say "1013-200", it is a old, original module and has been superseded with one that is newer that replaces one that says "GV" on it.

I worked on one that someone had tried three of those old ones and couldn't stop it from being crazy. I put the updated module and there was never another problem.

See if the power drops off to the circulator when the burner is running. It's not supposed to ever stop when the burner is running.

Cruisinfanatic

picture

There is a picture the 2nd or 3rd reply down from top. It is the newer 1013-200 module. The circulator does not stop running while there is flame

I appreciate your effort to help me resolve this

icesailor

Overheating:

Yes it does. It is flashing into steam because the circulator isn't running. The Limit control may be bad and not responding properly. A Professional could and should be able to figure out what your problems.

icesailor

High Limit/Overheating:

Whatever the High Limit is set at, turn it down by 20 to 40 degrees and see if it still does it.

Its called "Thermal Lag", the time that the control senses the high temperature and shuts off. Or the temperature drops and the burner has to start.

The "High Limit" is part of the safety circuit and when it opens, it shuts everything down. If lowering the limit control doesn't stop it, its the brain in distress. Or, you could have crud in the boiler and it is holding heat.

I have a friend who knows them well because he has worked on them since they came out and he loves them. They are bomb proof and like the Energy Bunny, it can take a lickin' and keep on tickin'

Sledgeyj

I know this topic is several years old, but I am having a similar issue where no matter what I do I cannot get sufficient flow. Bled the system of any possible air, replaced circulator, even put in a much bigger circulator. Friend who is a boiler tech says it is the Hoffman Specialty Mixing valve (same one mentioned here) that is bad and restricting flow. I am preparing to perform the service outlined in TSB SB0401R1, but to do so I need to remove the large cap of the mixing valve. Attempts with a pipe wrench were completely dismissed by the mixing valve, with the cap firmly holding it's ground and not opening. I am on to plan B. I have ordered a 8pt 3/4" drive mpact socket that will fit the square head. Plan is to use my pneumatic impact to open it. I have impact guns ranging from 350 ft. lbs to 1000 ft. lbs. Anyone see any reason that I cannot use this method to open it? In my opinion this should be less jarring and have risk of damage that using a couple 36" pipe wrenches. Thoughts?

JUGHNE

I got mine out without impact. IIRC, I sprayed it with PB Blaster several times, tapping on the plug with a hammer and it gave up the battle. I would caution against chewing up the corners with pipe wrenches. And only use a tight fitting 8 Point socket if it is a square plug.......I don't recall as I got it out after I replaced it with a ModCon.....it still sits in my basement waiting for a new home.