Thread: Wood stove with hydronic heating

Originally Posted by rijidij

As mentioned above, use good tradies who know what they’re doing.
A family member had a wood stove installed with an integrated water heater. The plumber, somehow, managed to seal the system. When it blew, it literally blew out the walls of the house. Pressurised steam and water is a lot more powerful than most people would imagine. Fortunately no one was injured or killed.

This is, as you comment, a critical requirement that it is not possible to seal the system. I am, in fact, uneasy about one aspect of my system - the pipes that lead into the stove have shutoff cocks so you can remove the stove without having to drain the system. This gives the possibility of sealing the boiler jacket in the stove. It is unlikely to happen except in the case that the stove or jacket has been removed for repairs, and then reinstalled and the stop cocks not reopened. They are behind the stove, and screwdriver operated rather than having a handle, and to get at them you need to remove the cupboard next to the stove.

This sort of system can be very dangerous, if sealed, as you can have a lot of energy stored in water heated above boiling point, and when pressure is released this energy is released as a pressure wave of steam.

It'd be pretty simple to plumb in a pressure relief valve from a HWS on the stove outlet before the shut off.

DL

Hi,
Run a 1 inch pipe from the top of the potential pressure pipe to the top of the header tank.
Run the overflow from the header tank to the eaves over a window.
In the unlikely event of pressurisation it will limit it, and give you warning. The stove may be damaged with an extreme overheating, but it won't explode.
Some sort of sensor could trigger an alarm as well if you wanted.
Cheers

There are lots of ways of ensuring there is pressure relief, just needs to be there. And this means the installer, presumably the plumber, understanding what he is doing, not blindly following a set of instructions or rules.

What about a geothermal heat exchanger system? Can provide both heating and cooling.

Another system that is very good, I was talking to a colleague from the UK with an old farmhouse, they were in the process of burying lots of pipes in the paddock next to their house as a heat sink for a liquid cooled split system, liquid being much more efficient than air and much more resistant to freezing in cold weather if it is buried a meter deep in the paddock. Sadly many of these technologies that are common in colder climes are not very accessible in Australia.

Regards,
Tote

And here's yet another option. I don't have one of these, but the claims made suggest they'd be pretty good. I think you'd have to design the house around the heater.

http://www.heavenlyheat.com.au

Don.