Central Boiler OWB Overheat/Not Circulating Troubleshooting Help

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SunHeart

New Member
Dec 15, 2021
10
Central NY
Hi All,

I have a Central Boiler Classic, installed in '98 by the previous owner here. It heats two separate spaces, a 1200 sq foot apartment and our main house, with 2 lines coming off of it with 2 different pumps, 1 for each space. Last night I noticed the temp in the house dropping, and the usually hot air from the furnace getting cool.

Went out to check the furnace and realized the fire was smoldering, and it seemed that it had 'shut itself down' a while ago as there was quite a bit of wood for the time. The damper was closed and did not want to open. I then noticed that there is steam coming out of the top of the boiler. It seems that the water in there is hot enough!

But isn't circulating. So I start to check the lines, underneath the boiler and in the different spaces. There are all relatively cool.

Both pumps seem to be working. I can shut them off from electricity and feel in the lines the stopping and then starting again of flowing water, and they sound the same. The previous owner mentioned that he replaced one of them (forgot which on) last year and that I should have one on hand in case the other needs it this year. I did have one. It seems like the one underneath the boiler that goes to the upper apartment was older, so I gave replacing it a try. No change.

The manifold to split the line into two right off the boiler is really hot. Right after that is the pump the goes up to the apartment. After the pump, the water line is a little warm, but should be just as hot I think, and isn't.

The other pump is in the basement of the house. The lines on either side of it are the same temp, kind of warmish, when they should be hot. The return lines are the same temp. The water lines under the boiler for this portion are the same temp, warmish (not cold but should be hot!)

Not sure where else to look to troubleshoot. It seems like a pretty simple set up. Why is it not cycling the hot water? Is there something else to check? The aquastat has never read a temperature since I moved in last year and I have just went with where it was set, and it has seemed to function well until now. Could that have something to do with this issue?

It seems that the water is constantly circulating, and the aquastat mainly controls the air damper, and has nothing to do with choosing when and how to circulate the water, correct?

Thanks for any pointers!
 

SunHeart

New Member
Dec 15, 2021
10
Central NY
Seems like it was the water level. I added water and after a few minutes the damper opened up and the fire got going. All lines are nice and hot now!

A functioning water level gauge would have saved a lot of time! Time to get one installed.

It also seems there is a significant water leak to have lost that much water in a couple months...

When I fill it up with water, it actually overflows from the roofline. I have also seen it dripping from the roofline at times. This isn't normal, is it?
 

salecker

Minister of Fire
Aug 22, 2010
1,795
Northern Canada
CB installed in 98
You might be on the last leg of the water heater
A CB from 98 .Close to 25 years old,no idea of how it was maintained.Has the water ever been tested?There a good chance it is leaking.
 

yooperdave

Minister of Fire
Oct 26, 2010
1,220
Michigan's U.P.
Change the pump in the basement of your house. "kind of warmish" is an indication of the pump not circulating water just as the same lines at the boiler "for this portion" are.

When that water isn't circulating, it is sitting in the boiler with those embers constantly warming it into that little bit of steam that you see. Make sure your vent cover is on the top of the boiler also.

What is wrong with the sight glass on the front of the boiler? You probably need to clean the plastic tube portion of it? That should be checked daily making sure the petcock is closed after checking.

How about an update?
 

SunHeart

New Member
Dec 15, 2021
10
Central NY
Seems like it was the water level. I added water and after a few minutes the damper opened up and the fire got going. All lines are nice and hot now!

A functioning water level gauge would have saved a lot of time! Time to get one installed.

It also seems there is a significant water leak to have lost that much water in a couple months...

When I fill it up with water, it actually overflows from the roofline. I have also seen it dripping from the roofline at times. This isn't normal, is it?
I cleaned out the gauge which mud daubers had plugged and it works now. So I check the water level regularly and fill it every 3-4 weeks. And now that I have a working gauge, I can not overfill it!

The solution to my original problem was that there was very little water in there, not enough to really circulate the warmth.
 
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yooperdave

Minister of Fire
Oct 26, 2010
1,220
Michigan's U.P.
I cleaned out the gauge which mud daubers had plugged and it works now. So I check the water level regularly and fill it every 3-4 weeks. And now that I have a working gauge, I can not overfill it!

The solution to my original problem was that there was very little water in there, not enough to really circulate the warmth.


Good job!