Milgo123

With the new extension being built to current regulations regarding insulation would it be fair to assume that the amount of heat required for the house would be no more than it currently is? Point taken regarding heat loss calculations though. Is that something that I could do or would you suggest getting it done professionally? Yes I understand that a manifold kit comes complete with the pump, mixer valve and zone valve. Would these items be wired back to the same wiring centre that the existing zone valves and heating controls/thermostats are wired to so long as there are enough connections available? I have the Wiser 3-channel programmer, 2 room stats and some trvs already so was wanting to utilise them instead of having to purchase new equipment. Is there any guidance regarding how much the input temperature can be reduced by a mixing valve or would it more likely vary by manufacturer? Finally, could you say what might dictate me having to use the Wiser controller as opposed to the standard wiring centre that the other zone valves and controls are wired to? Apologies if any of the questions appear really dumb, I'm just trying to get as best an understanding as I can so that I can have a useful input to whatever is installed and of course other posters/readers might find the information useful. Thanks for your quick response.

We have a new ground floor rear extension being added to our Victorian mid terrace and the intention was to make the change to a single zone (2-Loops) wet UFH in the extension (concrete beam & Block) and the adjoining back room that will be knocked through (timber suspended floor) this will entail removing 2 radiators from the old kitchen and back room. The more I investigate, the more concerned I get that is what I plan on doing is even possible...why you ask? My existing setup is a 15kW heat only Glow-worm 15r with a 200L UVC on S-Plan. Control is via a Drayton Wiser 3-channel (only 2-channels in use currently - DHW & radiators) The boiler is 7 years old and this setup has heated the house adequately for the past 7 years with the boiler output temp set at 58. The builders "plumber" has indicated that I would need a new boiler! although to be honest I have not had a conversation with him yet to ascertain the reason/s why he thinks that this would be the case. So in my head this all sounded easy! Control the new UFH as 1 zone from the spare wiser channel and the remaining radiators as 1 zone on the existing channel, DHW on its channel. My concerns... 1. Do I need to use actuators on the 2 loops on the manifold for the ufh seeing as they will both be in the same zone? Room temperature will be controlled by a Wiser wireless stat! 2. Do I need to use a Wiser ufh controller to control this single zone? 3. Water temperature differences required for UFH, radiators and DHW? Would the current 58 boiler output water temp be low enough for the UFH blend valve to lower it sufficiently to be the right temp for the UFH Hope the above makes sense and I'm possibly over thinking but would be glad of your thoughts. Thanks.