Fitting thermostaic mixing valve

[sargan]

Have a Thermal store for my underfloor heating & DMF.

The store which has a TMV on the DHW take off ... no problems there.

I attach a drawing of what it 'was', I have added the shunt pump circuit, used as a de-stratifying stir when DHW called for, normally provided by the boiler pump ... but this allows me to turn off boiler from May - Oct.
In practise I may add a time programmer(1day 1 ch) so that I can switch back to boiler each night for an Hr, in the event that there has not been enough PV input, it can top-up boiler so DHW for showers in morning etc.

Thermal store. TMV - Télécharger - 4shared

However the pair of take offs' for the underfloor heating (UFH) has no TMV the heating loop being directly connected to the transfer loop connections on the store.
The store temp is set by a thermostat to 60 degrees .......... that is the only control on the UFH loop to the manifolds (each zone then has its own thermostat & actuator)

As I have fitted a solar diverter unit, to dump excess PV energy into the immersion heater, it would be advantageous to run store hotter that 6o degrees (probably set to 75)

So I need to fix a TMV to the store connections ......... so started looking around for suitable 28mm valve, and came across this one:
Solar Thermostatic Mixing Valves (TMV)This may be eminently suitable, however it was the text (on the link) that say that normal TMV2 valves would not be suitable as they cannot work continuously at high temperature.
Is this correct, or some hype (my get that valve anyway as price s reasonable)

Secondly anybody care to recommend a good non-ferrous 28mm TMV ?

 

[snowhead]

However the pair of take offs' for the underfloor heating (UFH) has no TMV the heating loop being directly connected to the transfer loop connections on the store.
The store temp is set by a thermostat to 60 degrees .......... that is the only control on the UFH loop to the manifolds (each zone then has its own thermostat & actuator)

As I have fitted a solar diverter unit, to dump excess PV energy into the immersion heater, it would be advantageous to run store hotter that 6o degrees (probably set to 75)

The Under floor flow temperature was too high at 60, there should have been a blender valve at the manifold.

The Solar TMV has max input of 110, I think that'll cover your situation..

 

[sargan]

The complete system was supplied by NuHeat their design does not include a TMV. When asked they advise system is correctly designed to run without TMV.
With store at 65 loop temp will always be less ... I agree though a TRV is good idea. Hence going to fit one.
Any suggested models?

 

[ShaunCorbs]

The complete system was supplied by NuHeat their design does not include a TMV. When asked they advise system is correctly designed to run without TMV.
With store at 65 loop temp will always be less ... I agree though a TRV is good idea. Hence going to fit one.
Any suggested models?

is there a separate pump for the underfloor?

 

[sargan]

yes ... it is shown bottom right in both diagrams ... there is also a pumped DHW loop , but left that out of drawing for clarity.

Pump operates any time any of the 14 zones calls for heat. The loop is pressurised and has a expansion vessel fitted. (as does primary loop and pumped DHW loop)

 

[ShaunCorbs]

yes ... it is shown bottom right in both diagrams ... there is also a pumped DHW loop , but left that out of drawing for clarity.

Pump operates any time any of the 14 zones calls for heat. The loop is pressurised and has a expansion vessel fitted. (as does primary loop and pumped DHW loop)

If there's pump on the underfloor the tmv should be built into that for the underfloor so it should have one

If you could post some pics up if you don't mind

 

[sargan]

I'll try and scan in installation schematic.

 

[sargan]

Attached schematic ... change is as per my diag in post 1 .... added shunt pump & one way valve

 

[sargan]

Also this pic may help .... which is the above plus a TMV i.e. what I want to put in place.

As you can see in schematic in previous post above it was not included in the design for my system, nor in provided kit.
Been running since 2002

 

[ShaunCorbs]

Also this pic may help .... which is the above plus a TMV i.e. what I want to put in place.

As you can see in schematic in previous post above it was not included in the design for my system, nor in provided kit.
Been running since 2002

View attachment 26719

Look at item no 18

 

[sargan]

As I said above that is not included in my design, look at the schematic.. in Post 8 that is my system ..no TMV on heating.
The picture was just for info, to show parts .. as explained I intend to add TMV to match this picture.