Ufh pump required?

[jren37]

Hi guys
Apologies if this has been asked before I have searched for an answer but have yet to come across it.

standard install combi boiler running standards rads. good so far
Timber floor construction with void underneath
New bathroom installed with wet floor UFH
Happy to run this with the radiators and not separately. Will not require the UFH to come on separately to warm the floor…
So I’ve sorted my first query can’t install direct with a TRV as it’s under the floor and TRV will stay open so first part is a manifold with a blending valve it is set to correct temp (yes?)
Main question is - do I need a pump with it. Or will the combi pump suffice.
I feel two pumps on a combi system will not be helpful total bathroom UFH area is max 3m2..

happy to put one in if someone can explain the need but other wise I was looking at something like this With a blender
But cannot see the reason at the moment for an extra pump ?

https://www.ebay.co.uk/itm/26271861...c%3D|ampidL_CLK|clp:2047675&epid=2126945023


https://www.ebay.co.uk/itm/322334304728?hash=item4b0c9f29d8:g:x6YAAOSw3TFg2aG4

 

[Mr Chibs]

I think the blending valve is to make the water colder for the UFH, if it was went through the UFH at the temperature you have in your rads, it could be too hot and cause tiling to fail.

Your floor area may only be 3m² but when you lay your pipe you will be extending the pipework circuit.
Think mine are 200mm apart.

I can't see how you will be able to turn off the floor... if the room gets too hot. I don't think a TRV will help...

Mine room is run from a separate pump & thermostat so I can control it individually, granted larger than your floor.

I'd be interested in seeing other responses you get.

 

[Exedon]

What area is the bathroom floor? If not huge have a look at polypipe temperature limiting valve .
In effect a 15mm trv but operated by a probe in underfloor.
They do work got one installed in a bathroom at home been in 5 years with no issues.

 

[jren37]

Hi thanks for replies. I don’t really want to operate it separately as it’s just to top up radiator in there.
pipe is already laid in heat spreaders plates.
mots purely the connection.
wil have a blending valve just would like to know if the pump is necessary and what effect having 2 pumps will have. Don’t want it to be able to call for heat separately as that means starting to plumb and wire in separately to combi boiler.
I just want it to run alongside the existing system simple on and off. The main thermo is just outside the door so will soon turn it off if it gets warm