HughF

I'd skip the grant bit altogether - you sound technically competent, buy the bits and install it yourself. Provided you get a monoblock (which nearly everything in the UK is), you don't need an F Gas ticket. Treat yourself to a second hand press gun with some M and U jaws and you'll get the lot installed in no time.

Anyway, to drag this thread back in the correct direction... I'd like to thank those who own these units for dropping by and posting their findings, and for putting their information up on their own threads for others to find. It has been good to see what you have done with your installs. These units seems decent, with a fair spec for a fair price (compared to the other offerings). Vat at 5% would be nice though, as I'm not registered for VAT. It's going to be a hard sell to my wife, as she has her heart set on a combi (we don't have a large DHW requirement and she wants to get the cylinder cupboard removed and used for other things)... If gas goes up to 10p/kWh later this year and electricity stays at 28, it's a no brainer, we're getting an ASHP. But will we see gas go up that high? Self installed solar next... on our large, south facing, roof...

They are far, far, far more popular in the US, where a domestic water heater has, for years, been a simple UVC with and immersion in it. Perhaps look to the US for some reviews? But be aware that they will all be re-branded asian units. No-one makes this stuff anywhere else.

if you only need it for DHW and you don't need a heat pump for your central heating, just buy another heat pump water heater? Google will find you one...

My friend did the same with a fibre laser... much cheaper from China and all built with branded parts. Part of the attraction to move away from gas is to remove the requirement for me to get somebody with a gas safe cert to service the appliance. I can touch every other bit of plumbing in the house, so adding the heat pump into that list would be beneficial from a servicing point of view.

Well aware of how this works Marvin, I'm the chief buyer for my company and we import to the value of about 50k/year at the moment from China...

Phnix look decent, but expensive... Aircal also look pretty good, more reasonably priced... Sprsun build their units with Carel parts and panasonic compressors... I will start a avenue of discussion with some sellers and report back...

Cool, I’ll get mine from Alibaba then. Don’t need no stinking warranty, and I buy from alibaba weekly for work, so dealing with mainland china is a walk in the park for me. In all seriousness, there is some serious cashing in going on, as you say. Shame really…

I'm well aware of how heat pumps work and how to get the best out of them.... I'm looking to gut the whole heating system out of this place and re-plumb the whole lot. Probably manifold it because I've got the manifolds, and I've been accumulating tail ends of 16mm MLCP off facebook as and when. 25mm mlcp to the manifolds, 16mm to the rads. Aint got time for copper anymore. I meant flow temperature... But the supplier has confirmed my questions about that. 11.3kWh/day is fantastic, what size DHW cylinder are you heating with that? The Cool Energy product caught my eye as a half decent chinese offering that might give good performance, in a stainless case, that isn't stupidly priced. These things shouldn't be expensive, after all they're just a fridge

I've found the relevant posts, thanks. Interesting that it was the choice of Carel controls/EEV/Inverter that swayed David to this manufacturer. Nice to see some pictures of the internals in his thread too. As I said, tempted.... Just need to decide on a DHW strategy that doesn't utilise a UVC, no space anywhere near the bathroom for one. The wife wants the old cylinder cupboard for something else. Tempted to couple it to my 500ltr TS that I was going to heat with an anthracite boiler (before I got bored of the idea of burning stuff), stuff that out in the outhouse, and run a PHX off the side of it for DHW.

And these were from last november... I wonder what it will be like this year... *note, the display says monthty - the total was for the year till mid november, it's misleading.

I didn't anticipate there would be a cavity liner.... that's a good point. I should check that.

This '46 end of terrace has two, approx 10" square multi-holed air vents built into the outer leaf of the cavity wall, about 2/3 of the way up the wall. One vents the bathroom and goes to a sliding plastic vent on the inside (always closed), the other vents into the spare room where my wife has boarded over the inside vent. The cavity is full fill with blown in, chopped fibreglass. The vents are on the north and west sides of the building and we are on a hill, exposed to the prevailing south-westerlies. This house, is cold... Whilst I've got the scaffolding up on the gable end, I'm thinking about foaming and rendering these over in my quest to make this place less leaky. The plan is to add MVHR to the upstairs rooms including the bathroom at some point in the future, so these holes into the outside seem redundant to me now. I'm thinking about filling them up and rendering them over unless anyone thinks this is a terrible idea?

I was going to go for pipe-in-self-leveller 50mm buildup at 120mm spacing. I wanted something with moderate-fast thermal response, to match the overlay system I was going to add in the rest of the down stairs, and to appease the wife with her demands for a responsive heating system (although I'm hoping that when we get the UFH working on an ASHP, I can just set and forget the room stat) Hoping that I can get the floor build up level enough that I can just bang the self leveller down onto 200mm of PIR and be done with it.

Agreed, blocking the air vents seems like a disaster waiting to happen. I'd rather go for solid floor than beam and block (probably easier for this small space), just got to sort the ducting out I guess.

PWM driven solenoid valve - nothing more. I guess the controller can modulate the expansion vs a fixed expansion rate as you'd get in a capillary tube. EDIT: Nice video from YouTube:

Generic aliexpress sourced junk, shifted by a generic box shifter.... Yes it will make hot water, but expect it to be scrap after 4 years in the typical UK climate. I mean, it's cheap, but I'd say the Cool Energy inverter driven models, with european controls and EEVs are a better buy at twice the price.

Hi, long time lurker and first time poster (sort of)... I currently live between two homes, one in Dorset that my dad built in the early 70's out of demolition materials. That's totally off grid, although we do have broadband... My wife's place is an ex council end of terrace that was built in '46, and was last touched in the 80's as part of a council renovation scheme. I'm working on it as time allows... Hoping to pick up lots of help and information from this place. Hugh

We're looking at putting a single story rear extension under PD on our end of terrace which currently has suspended timber floors downstairs. My neighbour and friend, who is a builder, is going to do the work for us as I'm too busy with my day job and am a bit rubbish with a trowel and my wife wants standard masonry construction (I'm at home with sticks and a nail gun). Same neighbour put their rear extension on with a concrete slab floor, concreting over their air bricks. 1. Do I need to worry about concreting over my air bricks? My gut says yes. I'm not sure if the ventilation carries through to the front of the house, or whether the dwarf wall in the middle of the house is solid. There are air bricks at the front of the house too. 2. I want UFH in the extension, should I consider beam and block to retain an under-floor ventilation void? 3. The downstairs room which will open up into the extension needs some floor repairs and insulation, but I don't want to rip it all out and cast a new concrete floor in situ. Thoughts?

Nice quick reply from the supplier to some questions I fired over this morning: 1. DHW takes priority on all their heat pumps. 2. Weather comp applies even if the pump is running under a DHW call for heat. This seems like a limitation of the controller to be honest. Weather comp is either enabled or disabled. The standard warranty is 12 months, extendable for another 12 months if it’s installed and serviced by an accredited installer. The 5yr only applies to the compressor. That’s my understanding from reading the warranty doc on their website. Still, seems like a fair deal at the asking price. Build quality doesn’t look terrible from what I’ve seen of the older model on a certain danish youtubers video:

Hi, long time lurker, first time poster... Now that the Cool Energy heatpumps have electronic expansions valves and VFD driven compressors/fans, do you think they represent a good purchase at the current retail price of £3k for a 'up to' 9kW unit? Seems like quite a good offering although the warranty terms are the usual junk 'must be installed by an accredited installer' etc etc... The user manuals and installation diagrams aren't hidden behind a paywall/registration portal, which is encouraging. And these new units seem to have a separate 230v input for DHW or CH call for heat. I've emailed them to ask if the flow setpoint will automatically be changed depending on which call for heat is active, I assume so. Thoughts? I'm considering throwing one up the garden to replace our wonderfully reliable baxi bermuda back boiler.