Mixing (Cooling) Vented Hot Water Prior To Pumping.

[SimonG]

Customer has multi fuel stove doing heating and hot water.
Currently have an upstairs bathroom, bath, wc and basin.
Downstairs have a room about 6' square with just a wc in it.
They are thinking of turning it into a wet room, new wc, small basin and shower.

Easy option is an electric shower but not keen due to performance.

Currently cant pump it as water temperature above 65 and will cause issues with shower pump.

The stove doesnt seem to be plumbed in correctly as the cylinder sometimes needs the hot water running off to stop the cylinder over heating.

Now before I fettle the current heating side safely to give decent water control, is there anyway of mixing vented hot water prior to entry to a shower pump.

Obviously explained that current system isnt safe and needs sorting but all the customer sees are pound signs.

Answers on a postcode, thanks.

Cheers.

 

[Ben-gee]

Thermostatic mixing valve before the pump? Would need dedicated feed from CWS.

 

[SimonG]

Thermostatic mixing valve before the pump? Would need dedicated feed from CWS.

Thought of that but was concerned with it being vented, lack of head and the check valves on a tmv.

 

[Ben-gee]

Can get suitable for low pressure, might be called blending valve, often sold for solar stuff. I think last one i got was from BES.

 

[ShaunCorbs]

Tbh I’ve never had much luck with tmv3 on gravity

 

[Best]

I have used TMV usually fitted close to pump and no problems.
Also fitted TMV in an airing cupboard for mixed hot supply piped then to digital shower processor in attic above, used on similar issue with unregulated temperature at cylinder due to an often used open fire boiler besides oil boiler.
Digital gravity shower should have no problems with flow I guess, as is controlled basically with switching on, rather than flow valves need decent flow on a positive head twin shower pump

 

[Ben-gee]

On same lines as Best, would probably need to be negative head pump as flow through blending valve may not be enough to kick in positive pump.