HughF

Dragging this thread into May, I’m thinking about thermostats. The cool energy unit uses a carel controller (which seems to be designed for a commercial fridge) which supports programmable flow temperatures for either dhw or ch. These temps can be fixed or have a 4 point weather comp curve. This controller also supports numerous on/off timed programs. All good there. The controller doesn’t know or care about room temperature, it just reads two probes, one for buffer/llh temp and one for uvc temp. So I’ll need some sort of room stat, at least until I get the weather comp dialled in perfectly. Ideally I’d like one that has programmable upper and lower limits, the lower limit being the most important, so that a nighttime setback isn’t set too low by accident. At the moment we have an old Honeywell mechanical stat in the hallway (a stupid place really as the hallway radiator is massively undersized). What are my options for a good, simple to use, programmable stat that will work without a cloud provider account/internet access?

Some of my best purchases to date have been through eBay , and all at least 4 figures Another seller has a packaged 5kW system complete with a 150ltr cylinder, again on eBay. I’m sure you can find it. My calcs suggest I need 6.6kW with the current building fabric, I’m probably going to get an 8-9kW unit.

They've all sold now, along with the 5kW unit they had. I think the remote control is bundled with the FTC, from what I can tell from the manual. I asked them if they had any FTC units and they said that all they had were the monoblock units, and they didn't know what the FTC unit was.

I'd do this, just pack it out along that C stud

Gotcha, I thought the FTC6 was just the small control panel, I didn't realise that there was a separate PCB and more stuff required. I have since found the FTC manual which is quite detailed.

Thanks, I knew it probably ran an external circ pump but didn’t know about the external flow switch. Is there an indoor unit PCB that’s also required (that’s usually installed in the square box on the uvc)? Either my Google-fu is bad this week, or there isn’t much data out there.

You could just hack the render off, close the cavity properly, then re-fit the door in the correct place?

Pressed mlcp for me, every time. Easy to inspect the o-rings, and there’s two or more of them… Yeah, the pipe is 16mm and doesn’t fit anything, but what’s 1mm between friends 😂

I've spent some time this weekend figuring out where I can site my ASHP on my retrofit project. The cylinder cupboard is upstairs in the middle of the house and the flow/return runs in the upstairs floor void, front to back with 15mm drops in the corner of each room, nice 🤦‍♂️ We are end of terrace and are planning a rear extension under PD, and we want to site the ASHP on the narrow end wall of this extension, facing west (up the garden, pointing away from the neighbours)... I could bring the flow and return through the wall, then pipe it up inside the extension but it would then have to cross above two doorways before it meets the original back wall of the house, where it can go up the wall and punch through some cored holes, to pick up the run in the upstairs floor void. I'd need to box this in and I think it would look a bit rubbish to be honest. I'm thinking of how I can bring the flow and return in insulated (the proper, twin-pex-in-a-duct-with-insulation stuff) pipe, under/through the trench fill , through the hardcore layer under the PIR, then bring it up vertically out of the slab where it meets the wall. I want to have UFH in this new extension so don't want to trench across the slab/screed because it would give us an unheated area. Does this sound like a terrible idea? It's almost making me want to put in a suspended timber floor, to match the rest of the house, this would give me a nice void to work in where I could just snake the ducted pipe across, before bringing it up through the floor. Would a better idea just be to form a trench around the perimeter of the slab, deep enough to take a pair of 32mm MLCP runs (or 28mm copper, although I don't really like playing with copper anymore), this trench could then be covered over with a ply cover board. The neighbours did this when they moved their combi to the back of the new rear extension, they just formed the trench with some reverse shuttering when they poured their slab, then tiled over the top. I understand that the twin ducted stuff has a terrible bend radius though, so I assume I'm going to need to dig it pretty deep if I went with this option?

Does anyone with an intimate knowledge of the ecodan know what other gubbins are needed aside from an ftc5 or later, to get these running?

'Some' amps

I can't find the relevant 'bargains' thread to post this into, so mods, please remove/move if this is the wrong place. It looks like someone has some new, 12kW Ecodans for sale: https://www.ebay.co.uk/itm/185396297230?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=xznxbegYQBq&sssrc=2047675&ssuid=&widget_ver=artemis&media=COPY Not sure what other parts are required to get the running, I assume an FTC5 controller but I'm not sure about what's inside the box that normally gets attached to the UVC in Ecodan installs...

World heat, gotcha. Haven’t heard of them but I’ll check them out. Not too fussed about fitting layout but a large coil would be beneficial.

The next hurdle in the heat pump upgrade saga is the UVC. We have a cylinder cupboard but it’s small and has an old vented cylinder in it at present. I think I need to look at a slimline cylinder. Because I’m a cheapskate, eBay and Facebook have been worked over extensively and I’ve come up with that seems to be a good deal on a 150ltr slimline vaillant heat pump cylinder. slightly concerned by this bit of the data plate though ‘required temperature of indirect flow’ - why would it list this as being 80 deg C on a heat pump cylinder? And shouldn’t the coil volume/surface are be a bit more than the 5.6ltrs and 1m2 that the technical manual states? Apart from those two points, it’s new, a reasonable price and it isn’t miles away…. Another option that I quite like the idea of is something semi custom from McDonald water storage. I see from Trystan Lee’s video that he used one and it was almost the same size and shape as his previous vented cylinder. And they boast a 3m2 coil?

Reciprocating is a piston compressor, rotary is a rotary vane, scroll is an oscillating scroll

Rs485 based flow temp setting, from home assistant, based on time of day and who is home (with each family member preferring a certain house temperature)?

It was my guess from reading the installation blurb that when you set the 'temperature sensor' setting to air+water then it uses the internal air temperature (measured by the controller) as part of the control strategy, implying load compensation. But it's hard to find any concrete data on that. Interesting that you don't find the requirement to nudge the weather comp up or down. Do you have your curve matching the house losses and just leave the heating on 24/7/365, or do you use a timer + room stat. I'm trying to figure out the best/most appropriate control strategy for an ashp retrofit on an property I'm renovating and I'm looking at the options available from various manufacturers. Some have a impressive controller (LG, samsung), others (cool energy for example) seem to just use a buffer sensor and a 'call for heat' input from a programmer, relying on any room stats (if fitted) to drive the zone valves and pumps downstream of the buffer. The weather comp just varies the buffer target temp, irrespective of any room stats calling for heat. Not sure what's the best strategy to be honest and I'd welcome a discussion on that, I will probably start a separate thread.

Ok, that wouldn’t be an issue for me as the property is never unoccupied. How do you find the ease of use with the ai mode (weather comp)?

I've always purchased from seconds and co...

That's very good for such a modestly priced unit. I'm impressed by the offering from LG to be honest - how do you find the controller? From YouTube research it seems to be the nicest/easiest to use.

My ex-neighbour is the uk agent for m-tec (formerly Pico) heat pumps (Austrian), I’m looking into their specs to see if they have something suitable for our retrofit (yes, but eye watering prices). Their 12kW model can modulate down to 2kW which I thought was a pretty impressive range. Not sure if that is when it starts to cycle or not, I don’t have the details for that. I’ll try and upload spec sheets and find a tuv certificate.

This sounds like a nice plan, and is probably what I'd do. Clip rails down with a hilti gun, liquid screed.

I assume the iVT is the Cool Energy unit, inverter driven.

I have a sneaky suspicion that they left in in my garden because they know I'm a sucker for a deal