Hi all.. Maybe you can help me understand why my boiler blew up. We have a Burnham V73 model Hot water boiler system. We also have a coal/wood burner attached to this system. So we have 2 furnaces.Several months back, we had the furnace seviced. First the last heating year we have the front fire wall fall and it had burned the Gauge and Auqastat. It also cracked the cast iron plate on the front of the furance. We had the service technician come out and when he was here, we told him to do what needed to be done to the furnace. Replacing the nozzle, ect. We knew the auqastat needed serviced as it sparked on ignition. The service tech replaced the cast iron front, nozzle, oil filter, drained the expansion tank, front fire wall, and told us he had fixed the aquastat. On the service card he gave the furnace a 83.3/4% efficiency rating and rated the furnace excellent. We also asked him to adjust the valves going to the coal furnace as we were getting too much heat going to this furance and would like more heat forced to the upstairs rooms.

Now here we are sitting at home and the furnace is running and "BOOM" ! Husband goes to the basement and inspects the furnace. The pipe on the overflow valve had been blown off, it hit with such force that it make a dent in the cinder block. I call the plumbing company that did the work and explained what had just happened. Now mind you, its the weekend and I'm thinking "Weekend, going to cost me a fortune" for him to come out. Now at this time it has been about 6 months since they had done the work. We had it serviced late summer. The service tech comes out and looks at the furnace. He takes the side panel off and here we see a spray of water coming from the boiler section. He asks to see the service card from the last Tech. He looks at it and runs out of here like a cat with his tail on fire never to be seen again. He left and never came back. We had to call and ask where he went and what about turning the furnace back on as it was getting cold in the house. He told us we could turn the furnace back on, but it was going to leak.

What Happened? Why did our furnace blow up? We have never had a problem with this furance~!

 

It can be due to number of reasons: Obviously you had bad pressure relieve vale (the one that was blown off) otherwise it would open and let the pressure out.
Why did you have such a high pressure in the first place? Could be bad water supply pressure reducing valve, could be faulty expansion tank, could be bad high limit aquastat that let your water to boil and turn into steam. It’s hard to tell without actually troubleshooting. I would call that company and talk to the manager. I’m not sure about legal part of this situation, but I would definitely have them fix it first and than worry whose fault it is later.

 

I'm no expert but are you venting both devices into the same flue stack in the chimney ? I know my boilers instructions say do NOT ever vent a boiler into the same stack as a wood/coal burning device because of the varying temps in those devvices.

 

Hi Joe,

Yes they are both vented into the same chimmey. But at the time that this happened, nothing was being burned in the coal furance. The coal furance is more of a back-up to the oil furnace. It helps to keep the basement warm ,more of a radiator than heating at this point. But we do have it if the electric goes out! Abd this is the way it is set up when the Burnham was installed. The Burnham is only 10 yrs old.

Zag, the sad part to this whole thing is, I gave them free rein to fix anything that needed fixed. Money was not the issue with the service at that time. Just wanted it all done so the next time would be just a simple tune-up.

 

That is true in CT. I had to obtain a modification of code and have positive interlocks so only boiler could be fired at a time. The solid fuel unit can generate way too much draft for the oil burner.

Bigger issue: If something has physically blown off of the boiler, and it has internal damage, you'd better get another pro in there pronto to diagnose the problem! If the boiler really blew you're house probably wouldn't be standing.

Pete

 

Thank you all for your replies! Now you all have seemed to have shed some light on what may be another issue. When we had the Tech out for servicing, he also repiped both furances. Maybe we should have that looked at also. Its a darn shame that you have to sit and ask questions and watch everything that they do. After all, they are suppose to be the pro's here.

Once again Thanks!

Have a Great Day