OWB internal plumbing

[molson1959]

Seasons Greetings all.

I am new to the forum, so a thanks in advance.

I heat my home with an OWB, and done so for about 20 years, overall its been a good experience.

I live in central British Columbia, where we can get stretches of cold weather in the -40'f range for weeks at a time.
I have a friend in the forestry industry so i get my wood by the logging truck load fairly cheaply.

Just recently my boiler sprung a catastrophic leak, that was unrepairable, so i picked up a used one to get through this winter.

The unit i bought is a Cozeburn 450, its fairly old but is quite usable.

My question is, does anyone know what the internal piping looks like, with regards to the supply and return.

Both threaded ports are located near the bottom of the boiler, one marked "supply" the other "return".
I am guessing that the ports have some kind of piping on the inside going upwards in the water chamber.

When i first hooked up the boiler, filled it, and got a fire goin, all was well. unfortunetly the next day we were not getting any hot water into the house.
When i went out to investigate, the pump was making some horrible racket and was very hot.
Long story short, one of the fittings at the boiler leaked over night and dropped the level in the water chamber about 6 inches, this was enough to starve the pump and basically burn it out.
It seems as though the supply port is piped up quite high in the water chamber.

i am just wondering if should consider using the return port to supply the pump, if it isn't piped up as high as the supply piping.

Anyone have any experience with model or type of OWB.

cheers
mike

[woody_88]

So you're wondering about adding the new pump to the other side (return), it is on the incoming side from the factory? 

[hedgerow]

Mike
Welcome to the forum. I have never been around that brand but my Garn is set up the same way it pulls off the top has a draw tube inside the boiler. I had a leak last Dec and had to watch the water level close or I could burn up a pump also. I think they build them that way for two reasons hot water rises and if pulling off the bottom you may have a problem with pulling sediment into the system and ruining pumps and plugging heat exchanger's . If you do decide to pull off the bottom I sure would install a Y strainer ahead of the pump and get ready to clean it a lot for a while. 

[E Yoder]

Pulling off a lower port is much safer for the pumps. Most brands list a minimum inlet pressure, so having some water above the pump really helps prevent cavitation.
In your case though you don't know specifically how the internal piping is. You don't want to suck right off the bottom and get trash in the pump as was mentioned. Can you get a snake camera for your phone and run in an outlet or two? They're cheap on Amazon, I got one.