Hello everyone, wonder if anyone here can advise. Long story short, my underfloor heating is not getting warm enough.
It’s a wet system in my kitchen only. The rest of the house has radiators. The flow pipe from the boiler splits off to feed the UFH and the radiators/hot water cylinder.
The temperature gauge on the flow side of the UFH manifold (top left of photo. after the pump) rarely gets above 40 degrees, irrespective of what the mixer is turned to. Often it is lower, around 30 degrees even with the boiler firing. Water appears to be flowing through the tubes, as the flow gauge shows water flowing when the UFH thermostat is calling for heat and not when it isn’t.
The boiler flow pipe (bottom pipe going head on into mixer in photo) gets warm when the boiler fires up, but often the side of the T junction feeding the rest of the house gets very hot but the side feeding the UFH only gets lukewarm. (There is a circulating pump near the hot water cylinder upstairs which is constantly on, irrespective of whether CH/HW/UFH is on or not.. a separate issue I think).
Anyhow, the above (I.e. pump working, flow gauge flowing) makes me think perhaps the mixer is at fault. The temperature doesn’t really change irrespective of how far I turn it in either direction. Note that sometimes the return pipe after the mixer gets very hot, but I think this might just be because it joins the return from the rest of the house after a foot of pipe.
Could it be that the mixer is causing this issue where (hot) water doesn’t seem to be getting drawn into the UFH manifold properly?
I’ve had a plumber advise one of two things. Either a power flush of the UFH system: there is indeed a fair amount of magnetite in the water if we draw off some from the valves on the manifold.. could this just be clogging up the mixer and causing this issue where it appears water is circulating round (according to the flow gauge) but not actually allowing any “fresh” hot water from the boiler in?
The second suggestion was to just replace the whole manifold, including the mixer. I already tried ordering a new Reliance mixer but the connection for the pump at the top of the valve is at a sloped angle and the current, unbranded mixer it is flat, so it’s not possible to simply swap out the mixer valve and use the existing pump and manifold. So I will need (I think) to buy a complete manifold set and ask a plumber to fit it.
Any advice gratefully received.. a power flush seems quite expensive, certainly not much cheaper than a new manifold set and the plumbers time to fit it (it’s a 3 loop manifold I have but only 2 loops are in use - and both on a single “zone”).
I have attached a photo of the manifold in case it’s of any use. Happy to answer any questions if anyone can help shed some light on how to get the kitchen warm in time for Xmas! Thanks again.
It’s a wet system in my kitchen only. The rest of the house has radiators. The flow pipe from the boiler splits off to feed the UFH and the radiators/hot water cylinder.
The temperature gauge on the flow side of the UFH manifold (top left of photo. after the pump) rarely gets above 40 degrees, irrespective of what the mixer is turned to. Often it is lower, around 30 degrees even with the boiler firing. Water appears to be flowing through the tubes, as the flow gauge shows water flowing when the UFH thermostat is calling for heat and not when it isn’t.
The boiler flow pipe (bottom pipe going head on into mixer in photo) gets warm when the boiler fires up, but often the side of the T junction feeding the rest of the house gets very hot but the side feeding the UFH only gets lukewarm. (There is a circulating pump near the hot water cylinder upstairs which is constantly on, irrespective of whether CH/HW/UFH is on or not.. a separate issue I think).
Anyhow, the above (I.e. pump working, flow gauge flowing) makes me think perhaps the mixer is at fault. The temperature doesn’t really change irrespective of how far I turn it in either direction. Note that sometimes the return pipe after the mixer gets very hot, but I think this might just be because it joins the return from the rest of the house after a foot of pipe.
Could it be that the mixer is causing this issue where (hot) water doesn’t seem to be getting drawn into the UFH manifold properly?
I’ve had a plumber advise one of two things. Either a power flush of the UFH system: there is indeed a fair amount of magnetite in the water if we draw off some from the valves on the manifold.. could this just be clogging up the mixer and causing this issue where it appears water is circulating round (according to the flow gauge) but not actually allowing any “fresh” hot water from the boiler in?
The second suggestion was to just replace the whole manifold, including the mixer. I already tried ordering a new Reliance mixer but the connection for the pump at the top of the valve is at a sloped angle and the current, unbranded mixer it is flat, so it’s not possible to simply swap out the mixer valve and use the existing pump and manifold. So I will need (I think) to buy a complete manifold set and ask a plumber to fit it.
Any advice gratefully received.. a power flush seems quite expensive, certainly not much cheaper than a new manifold set and the plumbers time to fit it (it’s a 3 loop manifold I have but only 2 loops are in use - and both on a single “zone”).
I have attached a photo of the manifold in case it’s of any use. Happy to answer any questions if anyone can help shed some light on how to get the kitchen warm in time for Xmas! Thanks again.
