Any boiler repair guys here?

Polk user

I have a Peerless boiler MCB-097. Its about 15 years old and today for the first time about 2 gallons of water came out of the overflow valve into a bucket.

The valve is set for 30psi and when I turned on the heat to test it the internal water temp went from 170 to 210 and the pressure went from 12 psi to about 29psi and thats when the water started to come out of the valve.

The expansion take is the old style. It looks like a mini 55 gallon drum located above the boiler attached to the ceiling. I assume the issue might be that the tank needs to be drained. Is this correct?

I'm gonna relieve the pressure in the boiler, shut the intake valve to the expansion tank then drain the tank. Does that sound correct? Do you think I should replace the old tank with the new small style tanks????

Thanks in advance,


http://s251.photobucket.com/albums/gg299/DoitYourselfer/

mrbigbluelight

I'm not familiar with a Peerless boiler, but I assume you're talking about a home hot water radiant heat system ?

If so, doesn't 210 degrees seem on the high side ? A couple of more degrees and you have yourself a steam system.

You wouldn't happen to have a picture of the system would you ?

BaggedLancer

The expansion tank needs to be drained. Unless the tank is leaking don't replace it...not worth the headache. Even though it's not hard to do, whenever you start on projects like that it's a can of worms.

Drain the tank and you're good to go.

amulford

The expansion tank has an air filled bladder inside of it. Sometimes that bladder may rupture. I would drain the tank and change out the relief valve. If it keeps up, think about changing the tank.

I would turn down the high cut off, too. You're awful close to steam tempatures while under pressure and the possibility is there for some serious scalding if it flashes off.

Polk user

Thanks for the replys.

I drained the tank dry and then restarted the system and now the pressure stays about 12psi and there is no more leaking from the overflow valve. The tank is the old style 12 x 34 steel drum. Pics are here:

http://s251.photobucket.com/albums/gg299/DoitYourselfer/

Any idea where to turn down the thermostat on the boiler so I can get the temp to max out at about 180?

4406bbl

Sometimes there is no adjustment like that,just a high limit switch. I had a peerless and just adjusted the gas valve down to get the water temp I needed,remove the slotted regulator plug and there is a screw inside turn it clockwise increases pressure,counterclockwise decreases (cooler). If the gas valve does not have a regulator you may need to change it out. By turning it down your gas bill should go down as less heat goes out the flue. You should not need more than 150 degree water unless your unit is way too small.

amulford

If you look on the left hand side of your boiler, on the upper side is a gray box. That is a 2 way tempature switch. When the water in the boiler goes down to a certain temp, it fires the burner. When the water reaches the high setting, it cuts out the burner.

Pull the cover off and you should see two red knobs, or similar, with degree settings. One will say hi, one low...

Polk user

I will take a look when I get home.

Thanks!!!

amulford

Sorry, make that the right hand side, upper left corner...

Polk user

OK,

I opened the box and found this dial: (Honeywell S8610F Pilot module)

http://s251.photobucket.com/albums/gg299/DoitYourselfer/?action=view&current=IMG_0010a.jpg

http://s251.photobucket.com/albums/gg299/DoitYourselfer/?action=view&current=IMG_0013a.jpg

It looks like it's set at 190. I gently tried to move the dial but I don't want to break anything. How do I move the dial down? It seems the pointer is lodged between the grooves

The dial does not move at all. Is it supposed to?

amulford

It should, the pointer should move up or down and disengage from the teeth.

mrbigbluelight

Definitely lower that upper setpoint from 190 degrees.

4406bbl suggested 150 degrees; that doesn't sound bad.


At higher temps, one pain-in-the-arse thing that will occur is that any dielectric unions you have in your hot water radiant heat line will expand and contract more than you want; this wears out the seal inside them quicker, and they leak quicker.


Assuming you have a black iron to copper system (or vice versa).


Your house will heat up faster at 190 degrees, sure, but I assume you're no rush to spend money with your fuel provider (gas/oil).

Polk user

I can't seperate the pointer from the dial. Should I push the dial away from the pointer or do I try to pull the pointer up away from the dial. It seems like they are pretty well stuck together.

amulford

Try both. I looked up the controller but didn't find any info on adjustment. Maybe an email to Honeywell. http://http://www.honeywell.com/sites/honeywell/customersupport.htm

You have a hydronic (hot water) system, right? I like to see high/low controllers, it keeps the resevoir up an you don't use so much BTU's on demand.

IMHO, tankless on demand would be the optimum set up, but don't fix it if it ain't broke.

4406bbl

I think you can pull back the lever to disengage the teeth and then rotate the dial on that model. I would adjust the gas valve and leave the limit alone as 190 is about right. The limit is to shut the system down if the pump fails not to regulate heat. The idea is to get the system to heat the house and let the thermostat turn the burners on and off,if the limit switches do it the gas valve is adjusted wrong. Ideal settings are for about 1 psi of water per foot of rise (top of the highest radiator to basement floor) thats about 12-15 psi for a ranch,20-25 2 story. Water temp is ideal at the lowest temp that will heat the house on the coldest day,where I live 150 is fine at 20 below. The system will last alot longer this way. They also sell an airtrol valve that goes in the expansion tank that will let you drain excess water without draining the whole system,BUT I will bet if you turn the gas down your problems will be over and your comfort will be way better,thats how you get that constant feeling of heat hot water boilers are known for.

4406bbl

I had better add that unless its real cold you may not even need 150 water. Today it is 25 degrees here and my water temp is at 120,so try to use the lowest temp that will work for you. Do not assume that the original installer ever adjusted the gas valve as most do not,or the gas pressure could have changed,mine did when they put in new mains,the gas man did not readjust mine and it needed 2 turns to lower the temp. If you have the original owners papers it should tell you how to adjust the valve.

Polk user

Thanks for the info. I have all the manuals at home but I'm not sure I want to play with the gas valve. I think maybe I should have a professional come out and give the unit a once over and make sure nothing is really wrong. So is that pointer the "HI" limiter or is it the setting at which the water is going to heat up to? If it is the limiter then I guess it is better to have the gas turned down and leave the limit switch alone.

4406bbl

Yes that is the limiter.You are not playing with the gas valve,you are only adjusting it. You can adjust your gas valve yourself,do not be afraid of it. Remove the large slotted plug that is near the inlet,there is an adjuster slot down in the hole,turn it 1 turn counterclockwise at a time till you get the water temp down,then fine tune it when it gets real cold. Use your ears as a guide,if it sounds like more flame(rushing sound) turn the other way,if neither way changes the sound the valve regulator could be bad. As far as getting a pro make sure they understand what you want,as most will not take the time to do it right,(and can't for the price of a service call)they asume a gas valve is adjusted right at the factory,most are not and must be fine tuned in the field to make up for gas supply variations. On a typical valve the regulator will compensate for 4-10" of pressure so it can be way off like 50% if nobody set it on site. Believe me most heat units are not adjusted right.

Polk user

OK,

I found the gas valve and I marked it and then backed off 1 turn as I watched and listened the flame. There was no real difference so another turn I went. The plastic adjustment screw was almost down to the bottom and I actually had to turn it 6 1/2 times before it reduced the flame. The temp went up to about 140 so I turned it clockwise 3/4 turn and waited and the temp maxed out at about 165 degrees.

So now I'm at 165 degrees and the psi is steady at about 10psi since I drained the expansion tank. Does that sound about right?


THANKS FOR ALL THE HELP!!!!!!!!

4406bbl

Yes that should work,set your water psi by 1psi per ft of rise(basement floor to top of highest radiator) and you should be good to go. Now you need to get all the air out of the radiators and fine tune the gas valve 1/4 turn at a time,try to hit that 150 max. As you see very few servicemen will take the time to set your equipment right and fewer know how. I can't tell you how many times I go to someones place and see a gas valve way out of adjustment,even on units that have just been serviced.I bet you save a ton on gas now.

Polk user

Thanks for all your help. The boiler is actually about 4 feet below ground level. The house is a front to back split so the baseboards on the 3rd floor cant be more than 9 feet above the first floor where the boiler is located. The psi is steady at 10psi so I assume I can leave that alone? I also constantly release air from the plastic valve on the pipe exiting the boiler and I never hear any knocking from the baseboards.

amulford

I still would bleed the air if I could. They should have put a bleed valve at the highest part of the system. Just because you don't hear knocking doesn't mean it's not there. Bleeding it out helps the system to transfer more effiecently.

tonyb

Damn know it all union guys......:p:)

Polk user

I'll try bleeding it from the highest point if I can.

4406bbl, I sent you a pm.

4406bbl

Polk user wrote: »

I'll try bleeding it from the highest point if I can.

4406bbl, I sent you a pm.

Got the pm call me Saturday if you need to.