Hi all,
I have a Heatmiser UFH installation, 7-8 years old now. This week we noticed that a few of our heating zones were not warming up, even though the thermostat was showing the flame symbol. They were working fine last winter. I knew from when I looked at the installation in the past that the affected zones were all on the same Heatmiser wiring centre - a UH2.
So I'm looking to replace the UH2, but it's been discontinued so I need to 'upgrade' to something more recent. The UH4 looks appropriate, but I have an additional issue with the system, which I've been aware of for a while but just ignoring. If I'm going to have to buy some new hardware, it seems like the right time to try and address the second issue too.
I've attached a photo of our setup to this post. We have two manifolds: the one on the left runs two downstairs hallway zones, the W/C, and two downstairs bedrooms. Except it's a four-zone system - I'll come to that in a minute. The manifold on the right runs a single zone in our TV room, and three zones in our open plan kitchen/living area. Each manifold has it's own pump.
So the problem that I've been ignoring is that we've got five zones on the left manifold, wired into a four zone control panel. The way the original installers set this up was to wire a thermostat for one of the zones on the left into the control panel on the right. The problem with this is that the room would only warm up if another zone on the same control panel was also active - otherwise the pump on the right manifold was activated for the zone on the left manifold
We had this partially fixed a few years ago by doubling up the two hallway zones onto a single zone (controlled by a single thermostat), which freed up a zone on the left control panel to use for the other room (labelled "L" on the left manifold in the photo). However, this left a 'dead' wall thermostat in the hallway, and means we can't control the two hallways areas independently (not a big problem TBH).
So instead of replacing the UH2 with a UH4, I'm considering replacing both UH2s with a single UH8. Even though we have 9 water circuits, there are only 7 zones, as three water circuits are for one room (our open plan kitchen/living area).
My main concern with this is that a wiring centre can only control a single hot water pump. I presume I could simply wire both hot water pumps into the same connections, but that would mean that both pumps would fire whenever a single zone came on; regardless of which manifold the heating zone was connected to. I don't think it's very likely that a single zone will be on on it's own though: most of the time we've got the heating on, it's heating the whole house, or at least most of it.
There is another issue which is that the current UH wiring centres are almost twice as long as the UH2 units I've got,
So I think I have three options for how to proceed here:
1. Replace the UH2 with a UH4, hope I can fit both units in side-by-side (it'll be tight), and continue living with the 'dead' hallway thermostat
2. Replace both UH2s with a UH8, wire both water pumps into the same control unit, and live with the fact that both pumps will run whenever any downstairs heating is on
3. Get a plumber to move one of the heating zones from the left manifold to the right manifold, and then replace the UH2 with a UH4 (and still have the issue of space, along with addition risk of the water pipe not reaching, the mess created by moving the pipe, etc.)
So I guess my main question is: is replacing both the UH2s with a single UH8, and running both pumps when any zones are heating, the best solution? Or would you recommend doing something else?
Many thanks reading this and for any suggestions or advice!
Paul
I have a Heatmiser UFH installation, 7-8 years old now. This week we noticed that a few of our heating zones were not warming up, even though the thermostat was showing the flame symbol. They were working fine last winter. I knew from when I looked at the installation in the past that the affected zones were all on the same Heatmiser wiring centre - a UH2.
So I'm looking to replace the UH2, but it's been discontinued so I need to 'upgrade' to something more recent. The UH4 looks appropriate, but I have an additional issue with the system, which I've been aware of for a while but just ignoring. If I'm going to have to buy some new hardware, it seems like the right time to try and address the second issue too.
I've attached a photo of our setup to this post. We have two manifolds: the one on the left runs two downstairs hallway zones, the W/C, and two downstairs bedrooms. Except it's a four-zone system - I'll come to that in a minute. The manifold on the right runs a single zone in our TV room, and three zones in our open plan kitchen/living area. Each manifold has it's own pump.
So the problem that I've been ignoring is that we've got five zones on the left manifold, wired into a four zone control panel. The way the original installers set this up was to wire a thermostat for one of the zones on the left into the control panel on the right. The problem with this is that the room would only warm up if another zone on the same control panel was also active - otherwise the pump on the right manifold was activated for the zone on the left manifold
We had this partially fixed a few years ago by doubling up the two hallway zones onto a single zone (controlled by a single thermostat), which freed up a zone on the left control panel to use for the other room (labelled "L" on the left manifold in the photo). However, this left a 'dead' wall thermostat in the hallway, and means we can't control the two hallways areas independently (not a big problem TBH).
So instead of replacing the UH2 with a UH4, I'm considering replacing both UH2s with a single UH8. Even though we have 9 water circuits, there are only 7 zones, as three water circuits are for one room (our open plan kitchen/living area).
My main concern with this is that a wiring centre can only control a single hot water pump. I presume I could simply wire both hot water pumps into the same connections, but that would mean that both pumps would fire whenever a single zone came on; regardless of which manifold the heating zone was connected to. I don't think it's very likely that a single zone will be on on it's own though: most of the time we've got the heating on, it's heating the whole house, or at least most of it.
There is another issue which is that the current UH wiring centres are almost twice as long as the UH2 units I've got,
So I think I have three options for how to proceed here:
1. Replace the UH2 with a UH4, hope I can fit both units in side-by-side (it'll be tight), and continue living with the 'dead' hallway thermostat
2. Replace both UH2s with a UH8, wire both water pumps into the same control unit, and live with the fact that both pumps will run whenever any downstairs heating is on
3. Get a plumber to move one of the heating zones from the left manifold to the right manifold, and then replace the UH2 with a UH4 (and still have the issue of space, along with addition risk of the water pipe not reaching, the mess created by moving the pipe, etc.)
So I guess my main question is: is replacing both the UH2s with a single UH8, and running both pumps when any zones are heating, the best solution? Or would you recommend doing something else?
Many thanks reading this and for any suggestions or advice!
Paul
