Water jacket problems

[elbowpipe]

In our self-catering cottage, we have a hot tub fired by an external wood stove with a water jacket. The cold water pipe delivers from the tub to the bottom of the water jacket and the heated water rises to the pipe at the top which delivers back to the tub. We had guests recently and they reported water leaking from the top of the jacket into the firebox making the tub unuseable.

Is this just wear and tear? (It's 2 years old). Or if the stove is overheated can this happen? Or, can rough loading of logs into the stove (ie. ramming in logs) cause the seal to be broken?

They want their money back, but if they caused the damage, I'm reluctant to do so.

 

[Fred61]

If you don't have a return water protection device installed chances are your problems are self inflicted and not the fault of the tenants. hot tub water which is in the temperature range of 102 o 106 degrees entering the boiler will create condensation in the fire box and it will corrode through in short order. The symptoms you describe fit this situation to a tee.

 

[elbowpipe]

If you don't have a return water protection device installed chances are your problems are self inflicted and not the fault of the tenants. hot tub water which is in the temperature range of 102 o 106 degrees entering the boiler will create condensation in the fire box and it will corrode through in short order. The symptoms you describe fit this situation to a tee.

The stove was supplied and fitted. What does a return water protection device look like? There's a smaller pipe emerging from the stove, underneath the cold water pipe.

 

[maple1]

That plus the fact you have oxygen rich open water running through the stove - a prime recipe for rust.

Heating a hot tub with a wood fire should be done with the aid of a heat exchanger in between. And if the wood fire side isn't closed & pressurized, it should be well treated with the proper anti-corrosion chemicals.

EDIT: Plus, the typical hot tub chemicals could actually promote corrosion. Is this a home-built kind of heater?

 

[elbowpipe]

That plus the fact you have oxygen rich open water running through the stove - a prime recipe for rust.

Heating a hot tub with a wood fire should be done with the aid of a heat exchanger in between. And if the wood fire side isn't closed & pressurized, it should be well treated with the proper anti-corrosion chemicals.

EDIT: Plus, the typical hot tub chemicals could actually promote corrosion. Is this a home-built kind of heater?

Hmmm, the tub and stove were supplied by a one-man operation, so you could be right. This has been very useful, thanks.

 

[Marshy]

Sounds like it's possibly a stove retrofitted with a hot water pipe inside the firebox like Thermo-built coils.
(broken link removed to http://www.hilkoil.com/Technical.htm)