David78

Just wanted to check these are the nuts that I need to unbolt after closing the red and blue tap? Then i swap over the manifolds, but once I reattach I probably will have lost some water, is there anything I need to do to ensure the system is refilled correctly and there is no trapped air?

Just wanted to say a big thank you for all the advice I have received from everyone, I really would have been lost without it. Will be swapping over the manifold.

It's the same manifold for both old and new extension

Thanks @PeterW for the advice, much appreciated. Attached is a photo to the left of the manifold, just caps with one spare zone.

The bottom pipe is the one which gets hot first. Is that correctly setup?

I hope that helps, I was told by someone that the pump is the wrong way round which makes sense as the out pipes are warmer than then in pipes. Will be looking to change this

I'm not technical but I believe so, its attached to the manifold, see photo

Gas

I noticed that on the opposite side of wall I have ventilation bricks which is possibly what's creating the draft in the room with underfloor heating. I assume these should not be closed off as the joist need ventilation?

I suspect you are right, I feel a big draft from the tiny gaps between the floor boards a d the skirting board, so there must me some hole. Thanks for the advice, will look into it

I suspect you are right, I feel a big draft from the tiny gaps between the floor boards a d the skirting board, so there must me some hole. Thanks for the advice, will look into it

The builder to put some insulation between the joists where previously it had an air void. He then pinned the pipes to the insulation and then covered it with engineered wood flooring 15mm thick

Hi all, I'm going to apologise in advance as I have limited technical knowledge on underfloor heating and general construction. I was hoping to get some advice on our wet underfloor heating installed 3 years ago. Its one system across multiple zones. It works really well in the new extension where we have concrete flooring with a microscreed finish. However in the old part of the house we have a room with a joist flooring and engineered wooden flooring and here the heating is never warming up the room. The floor boards are always cold and a thermometer in the never shows the temperature going up. I checked the in and out pipes on the manifold and all appear warm. I decided to rent a thermal image camera to see if I could spot any problems. All the pipes are appear to be working but the temperature readings are very small 21C compared to the new extension where we get 25C.. See attached photos I am wondering if this is a normal or expected output? We as a family freeze in the winter and never tend to stay in the room long because of the cold. I don't recall how the builder installed the pipes but I do remember some insulation went in first then the pipes and followes by the flooring. I assume this is OK? I'm wondering maybe the heat is getting lost by the fact we have an external solid wall so insulation in the room is clearly not as good as the new extension but I it does not explain why the floor is stone cold. Any advice? Ps I did spot the builder placed the pump in the wrong direction so the out flow is going through the in pipes and therefore the flows which are set to max do not register any flow. I'm having this fixed by a heating plumber so that might give us more control.