Is the extra pump and thermostatic valve necesary with a condensing type gas boiler?

[eddie3000]

Hello everybody! I'm new to this forum and I'm popping in to ask this question. Here is my problem:

I'm having underfloor heating installed at home. It's going in a 7cm thick cement screed. The whole house is going to have this type of heating. I have the understanding that the ideal temperature for that type of floor would be under 30ºC. I have seen many manifolds on the internet with a thermostatic valve and an extra pump. Wouldn't that be unnecessary? Wouldn't it be fine to connect my new condensing type gas boiler straight to the underfloor heating manifold straight and set the temperature in the boiler to be 30ºC or less? The installer insists on installing the thermostatic valve and water pump, but I reckon it's not necessay because the type of boiler I have. It would be necessay if the boiler couldn't handle that type of low temperature right? Am I wrong? I think the installer is just trying to sell me the extra kit and charge me an extra 400€.
Thanks.

 

[Atouchofgas]

Re: Is the extra pump and thermostatic valve necesary with a condensing type gas boil

Unfortunately you are wrong, depending on the boiler you have, how would the hw heat above 30?
Also your pump isn't strong enough to pump it round all the circuits

 

[oz-plumber]

Re: Is the extra pump and thermostatic valve necesary with a condensing type gas boil

The ideal floor temperature may be 30 C, bit you have to have a higher water temperature to achieve that floor temperature.

Without going into design principles re: water temperature, floor temperature and room temperature. I would say that your contractor seems to know what he is talking about.

Your post ( rightly or wrongly ) comes across as if you want fuel to confront the contractor that he is incorrect and you are correct.

It's your house, if you feel confident that you are correct, why don't you specify to the contractor to do what you request, and, if the system doesn't work effectively, that you will be responsible for the cost of rectifications to make it right.

At the end of the day, all the contractor will have to do is add a pump and a thermostatic at the manifold.

PS: get him to run additional wiring required for the additional pump at the time of installation

 

[gassafe]

Re: Is the extra pump and thermostatic valve necesary with a condensing type gas boil

If you think so badly of the installer do it yourself as you obviously know best...

 

[SimonG]

Re: Is the extra pump and thermostatic valve necesary with a condensing type gas boil

Installers correct. OP wrong.

 

[jonnyswamp]

Re: Is the extra pump and thermostatic valve necesary with a condensing type gas boil

You obviously have no confidence in your installer, even though he's right
My advice to you, do more research
My advice to installer, get another customer

 

[Dotty]

Re: Is the extra pump and thermostatic valve necesary with a condensing type gas boil

Think the op gets the point now.

Thread closed.