msmithuk77

This is great thanks!

Could you expand on what to look for? I suspect this will be a step to far for my ambition

Excellent - thanks again!

Thanks for the info @JohnMo. All makes sense though, I'm going to do more research into the low-loss header. Another QQ if you don't mind. I'm going to use 2x Flamco Pump Group for the UFH (mixed) and Rads (non-mix). I have a quote from an UFH company and they have included Grundfos EuP Pump (22kw) and a Grundfos Pump Station. I'm assuming I don't need these with the Flamco Pump Group as I'll have these in the system already. Correct?

Hi, I'm new on the forum and seeking some advice and confirmation on my approach to my heating system. We are replacing all the plumbing and heating in a recently purchased 80s house. What I wanted was the following: Domestic Hot Water Priority System Boiler with unvented hot water tank Weather compensation UFH Downstairs Rads Upstairs After some research and discussion with my plumber, I have the following details: Valiant kit: Boiler Valliant Ecotech Plus (new model) (I wanted Viessman, can get Vaillant and I’m happy with this): Wiring centre Weather Comp 2x SensoComfort Controllers (1x DHW and UFH, and 1x Rads) Unvented cylinder VR10NTC temp sensors: Unvented Cylinder pocket Flow to the Rads (after pump group) Flow to the UFH (after ump group) 2 Port Diverter splitting the flow from the boiler to A) the DHW (for hot water priority) and B) Rads and UFH Low loss header to manage the flow temps and reduce cycling Pump groups (1x Mixed for UFH and 1x non-Mixed for Rads) The UFH will be on an open loop and only controlled by the boiler and flow temps at the manifold. The Rads upstairs will have TRVs (non-smart). What I'm looking to clarify are the following comments or suggestions to make sure I'm making the right decisions: We should have Heatmiser Neo thermostats in each room/zone (as far as I’m aware they cannot modulate the boiler and defeats the points of WC) The Low Loss header is optional/unnecessary for my system but will make it more efficient. The open loop UFH will make it very hard to manage the temperature in the individual zones and suggestion actuators with smart controls. We have been suggested Vaillant ecoTEC Plus 635 35kW. Our house is detached, 4 beds, ~200 square meters, 2x bathrooms and WC. How do I make sure I’m not getting an oversized boiler or is this just about right? Thanks for any help/thoughts. The diagram attached shows the system borrowed largely from a really helpful design found online. System Gas Boiler.pdf