Antonb182

@JohnMo Thanks for the heads up on the small relay. Saves me the pain of trying to figure out what i'd done wrong at a later date. Have ordered from the link you sent as this looks like an ideal solution for me. @Mike This is actually a really interesting setup and I think that with the bits I've got in place, I now have something that operates in a very similar fashion. The issue I now find myself with is that the Willis runs hot and cool, intermittently. I've matched it's output temp to the mix temp on the manifold mixing valve (I'm aware I shouldn't really need one if the input is already the correct temp), but the on off nature of this is preventing the room from getting above about 18-19 degrees. It's a SIPS build and well sealed, So heat loss from the room isn't the issue but even after running it for over 24 hours, the return temp is well down compared to the input, but that damned Willis refuses to stay on. Manifold says i'm running at approx 3L/min.

I hadn't thought about runaway heat from the Willis, but will definitely consider that too . I had in mind to use something like a Salus 16a relay (Here) (or a more robust Drayton heat switch) and run the call for heat from the wiring centre directly into it, which I guess should then control the on off in line with the rest of the vales/pumps being activated. If anyone has this setup already in place, I'd be super interested to actually see a pic of how you're already running.

OK, so i'm adding wet UFH to our outbuilding, slab and pipes are in, manifold is set up and i'm now at the stage of getting it up and running, but I have some questions, which while not insurmountable, I'd definitely benefit from some more sensible/learned opinions on. First one is the Willis. I'm planning on using it to heat two relatively small spaces (approx 25sqm each) and i'd be super surprised if they ever both needed heating at the same time, so I think i'm going to be OK with a single Willis. However, what i've not figured out, is how people are switching them on/off depending on the system needs. As far as I understand, there's no switched live on the unit, so I assume i'd need a relay/switch of sorts between the (always on) spur and the unit. Is this what people generally do? If not, how are you guys controlling the on off of the Willis? Not sure if it makes a difference, but the whole thing is going to be controlled via the heatmiser UH4. Secondly, because I already have them, I was planning on using Hive to control the two rooms in two separate zones. Which in my mind, makes perfect sense, one receiver and one thermostat for each zone. Has anyone else done this already and how did it go? I still have the possibility to switch to something more easily integrated, but i'd definitely rather use something I already have.

The response you received is almost identical to the one I got a few days ago. I'd be interested to know which route you took and how it went. I'm probably not going to export, but it might be helpful for future dealings with them (from my own perspective) if you took the G98 with the aim of them reinforcing the network (and they did). Did you make a decision yet? Also, and I know this is a very noob kinda question...on the G100 form, power station capacity is just the max that I can supply to the network, correct? so a 6kw inveter tied to a 10kwh battery with max output of 5kw), power station capacity would still only be 6kw? I only ask because the SPEN guy seems to be changing his mind and leading me on a merry dance.

Only 2 of the rooms are going to need heating over the winter and the requirement (can't find it at the time of writing) is so small that even a 4kw ASHP would be overkill. My thought was to use an aircon system instead then it can also be used for cooling in the summer. I realise this might seem counter-intuitive to save 1500 on a boiler, to then spend it on aircon, but it would definitely make the space more adaptable year round. I do plan on looping in the UFH as a "just in case" option for future, but the a/c puts out about 1200 BTU's, which should be more than enough to make each space comfortable even in the middle of winter.

Recently I was given a 14kw heat pump and associated cylinder. Now, we're putting up an outbuilding, it's 100sqm with walls at 0.1 and ceilings at 0.11 (sips build with superfoil). Obviously, the heat pump is going to be massive overkill to provide heating and DHW. However, I was wondering if anyone has just used the CYLINDER from a heat pump as an immersion heater for the DHW without connecting up the heat pump? It'd save me buying a new immersion heater at £1500, and I like the idea of using something I already have if at all possible. Any thoughts on whether this is possible? The heat pump is the puhz-hw140vha2 and the cylinder is ehpt25x-ukhcw. Any thoughts or ideas would be hugely welcome

Hi all, new to all this, including putting up buildings, but just about to throw up our first outbuilding (trying to figure out how to heat it), and then moving onto the main house with Enerphit in mind. Please help!