Solid fuel heat source & pipework

[oldbutnotdead]

The Wiki has answered a few questions but can't find an answer to this particular query....system is still in design/mulling stage so no desperate panic here

If your heating/hot water system incorporates a heat store connected to a woodburner, does the DHW pipework between heat exchanger and taps/shower/other end use have to be copper?

And if the answer to that one is a YES, would a tempering valve after the heat exchanger (set to 48 deg C) be acceptable as a 'control system' (so that plastic pipework can be used from valve plus a metre or so to end uses) - this would be as well as the overtemp dump valve which I can't remember the proper name of but if water in primary circuit/heat store starts boiling said valve opens to allow boiling water to escape to safe drainage & thus permit cold water to enter the system to cool it down).

I'm not a massive fan of plastic pipe but getting a copper hot water feed to one particular location is going to be a bit of a mare.

 

[Agile]

As far as I am aware any open vented hot water system will never exceed 100C so that plastic pipe can be used.

Tony

 

[oldbutnotdead]

Happy days- ta chap, physics seemed to indicate that but Part G is a tad opaque on the details

 

[Agile]

Its the primary pipework on the heat source where it should be metal.

Since the heat source is uncontrollable the expectation is that it could exceed 100 C although in theory that should not happen when its open vented as the water would just boil off.

But faults and blockages can happen!

 

[oldbutnotdead]

Thanks again- yes the rough sketch so far is woodburner in the kitchen fireplace (which the gf reckons is begging for an Aga but she's no cook and neither am I so sod that), heat store in the alcove next to it as high as I can get it and linked with 28mm copper. Don't like pressurised systems, failure consequences are a bit high and in a house with a loft I can't really see the point.

 

[Agile]

You cannot have a sealed system on an uncontrollable heat source.

 

[oldbutnotdead]

Suits me- don't like them anyway. Have another Thanks on me