HughF

It’s almost certainly just a bent mess of spreader plates under the chipboard. It’s a miracle it works at all really…. Shocking install.

Quality workmanship there 🤦‍♂️

Use the pump in the ashp to drive the rad circuit, use close coupled Ts on the return to hydraulically separate the ufh mixer/pump station. Use an ivar unimix3 pump station (eBay seems to have some on occasion) or if you want to go fancy, an esbe valve and a separate weather comp valve controller. I probably sound like a stuck record by now, but have you considered Cool Energy? Their 9kW offering is very capable, sensibly priced, and they sell direct. The system is built on a Carel industrial refrigeration control platform and is very capable. And their installation instructions have plumbing diagrams for a variety of standard configurations. @dpmiller has had his machine running for a while now and seems pleased with the performance of the package. He self installed.

I couldn’t agree more - it’s pure profiteering by the so called professionals. Any reason why you’re so keen on an aerotherm plus, and why you’re so keen on a warranty? I genuinely feel you’ll do a better job and save yourself a ton of cash doing it yourself. The plumbing couldn’t be simpler. Tank temperature sensor, 3 port diverter valve, power supply. Just watch YouTube 🤣 All jokes aside, all the g3 stuff is in an approved document, just follow that. Pay BC to come and inspect it, or don’t.

It’s highly likely that your Grant ashp has been installed with too many zones and on/off thermostats. The Grant (Chofu) controller is quite good, but grant decide to try and make it as easy to install as an oil boiler, so fit it with on/off controls that cripple the COP. Ideally you’d have the WC setup for the rads, and a separate WC’d Esbe valve (with associated Esbe controller) on the UFH manifold. Your UFH, did you say that was a spreader plate system? Any photo’s of how well (or badly) it was installed?

You’re asking for load compensation, a reduction in flow temperature occurring automatically when the room temperature reaches the target. Not all heat pump controllers offer this. Not sure if the Chofu one does or not.

Agreed, the Prana unit looks like a good combination of price/performance….

Why would you want to pay an extra £5k or more to an MCS certified monkey to then claim the grant? And no, you don’t need F-Gas for a monobloc… I have a pretty low opinion of MCS to be honest. My 9kW inverter driven machine was £3100 delivered to my door…. £500 for a heat pump cylinder, underfloor pump/mixer was £200, and the balance on a full set of new rads. Managed to pick up a couple hundred meters of 16mm wras approved Alpex for £20 off facebook, change out of £5k for a new heating system. Did my own heat loss and rad sizing using the Freedom toolkit and cross checked it with heatpunk.

You sound like you know what you’re doing, and you’re going for full planning on this new build so there is zero reason for you to go through an MCS installer and use their heat loss calcs. Buy the unit (whichever unit you fancy) and pay your plumber to fit it, or do it yourself. It’s really not complicated.

Found something suitable: https://www.stoveworlduk.co.uk/eco-design-stoves/ecosy-newburn-4-idyllic-4kw-defra-approved-eco-design-ready-multi-fuel-stove And not extortionate either

I don’t think I’m going to win the ‘no stove’ argument with my wife so I’m looking at what our options are for a multi-fuel (she’s insisting on something that can burn coal as well) stove with external air supply, that’s sub 5kW. Does anyone have any pointers of where to look?

Single story rear extension, 5m x 3m floor area, English regs. It's either one of these or trickle vents, and I'm not going down that route.

I'm at the stage where I need to look at dMVHR for a rear extension, thanks for the mention of the Mitsubishi Lossnay system, that's something I hadn't considered. So far, I think my options are: Partel Lunos e2-60 @ £1445 a pair (https://shopuk.partel.com/collections/ventilation-with-heat-recovery/products/e2-60-inc-transformer-controller) Europlast Eextra @ £179, a single unit required (https://www.ventilationland.co.uk/product/40954/decentralised-mvhr-unit-o100-mm-with-switch.html#revtitlelnk) Ecostream Prana 160 @ £590, a single unit required (https://ecostream.org.uk/prana-160/) - thanks to @JohnMo for bringing this nice unit to my attention Mitsubishi Lossnay VL-100 @ £250, a single unit required (https://www.ebay.co.uk/itm/185312135737?ssPageName=STRK%3AMEBIDX%3AIT&fromMakeTrack=true) Can anyone suggest why the Partel unit is so expensive, and for that matter why the Europlast Eextra seems so cheap?

The FAQs I've read from two window suppliers say otherwise, but from reading ADF1, it seems that a single room heat recovery ventilator is acceptable (as expected).

External boiler control signal from the LG controller can switch a 3 port diverter over to the oil boiler, the contacts in the three port can close and send a switched live to the oil boiler….Seems pretty simple to me.

Interesting, cheers. I'll start a line of conversation with my builders BCO and see what he's happy with. I know my wife will go mad if we're forced to have trickle vents, she hates drafts.

As in they can be fitted after delivery? I suppose it's just a router job after all. My supplier will manufacture them with/without depending on what's required. I don't need to get them ordered so soon, but I'd rather they were at least on the way to being delivered and not holding things up. I'm ahead of the curve on the new heating system, I'd like to get the windows/door finalised with my wife and ordered up before I find something more interesting to spend my cash on

Damn..... I'll talk to my builder and get him to have a discussion next time he's out on their current site.

We are starting on our single story rear extension next spring and I'd like to get ahead of the curve and get the 2x windows ordered up. My understanding of the latest regs is that BC will expect trickle vents, or 'other ventilation'. I'd prefer to fit a dMVHR through the wall to handle air changes. Either a Partel Lunos, or something similar. I don't have trickle vents on the rest of the house. Can I go ahead and order my windows up without trickle vents? We will be using the builders preferred BCO, not the council officer.

Just to add, Cool Energy do heat pump water heaters... might be worth a look. They are a helpful bunch up there. https://coolenergyshop.com/collections/ecostore-ecosyn-exhaust-air-heat-pumps

Well, the pipe is down and we blew it up to 5bar with the compressor... I was mistaken, single manifold was used. They removed the loops from under the stairs, under the baths/toilets. 16mm pex stapled down, 100mm concrete going over the top on Saturday. 19m3 pour.

One less thing for meddling fingers to fiddle with too.... the rad circuit is being sized for 45 degree flow (I'm already unpopular with the rad sizing at that temp) so dT7 it is then. I didn't know they auto switched to dT4 below 30. What a genius device.

I’m proposing manifolding my new rad installation for various reasons (mostly I don’t like hidden fittings) and that got me thinking, would I be mad to ditch the lock shield at the rad and just throw a salus self balancing actuator on each manifold port? They’re programmed for dT7, which would be spot on for my ashp install.

More details required, please. Rads in the rest of the house? Gas boiler make and type? Type of wall thermostat downstairs?