Bramco

You obviously live alone... Where thermostats have a display, isn't that what the display is?

You're making the assumption that someone in the house (you know who I'm talking about) can guess the temperature without looking at the app - ain't gonna happen..... 😄

Could do but... In our setup, we only need to run the ASHP at night to batch charge the insulated slab. When it is cold, all the rooms need the full 6 hours or so. When it is less cold, the thermostats will cut off the flow when the set temperature is reached. So for the downstairs bedroom it cuts the flow off earlier than the other two living area zones - the set point is lower. I do set the thermostats in 1 hour intervals starting a couple of degrees higher than needed and decreasing the setpoint every hour. This makes sure that the thermostats don't dick around with the ASHP by tuning it on and off at short intervals. Again this seems to work fine.

Thanks for the suggestions guys - I'd put solving this on the back burner as we had a workable if slightly more expensive solution - think I probably need to give this a bit higher priority on the to-do list.... The UFH buffer tank is a smaller Newark tank (140l) - earlier when I contacted them, they said they put either one or two coils to get the 3m2 surface arear depending on the size of the cylinder. So I guess they always put two in on one that is 140l. Our 300l DHW tank has only one.

@Wil thanks and I know how to do the change manually - there's a few owners on another thread trying to work out how to do it automatically. I wonder if we maybe haven't the same unit - mine is wired using pairs on a cat5 cable, not through an rj45 connector. Do you have the pinout for your connector.

Thanks

I know I do.... 🙂 Long discussion here -> https://community.openenergymonitor.org/t/water-hammer-noises-and-heat-pump/26263 And you've been short changed - mine has a couple of those. 😄 and they haven't worked on the air trapped in the corrugations in the DHW tank.

It's been stated many times...... 😄 Sadly we have a DHW tank with an ASHP coil (3m2) BUT it's corrugated which leads to a lot of noise from air trapped in the corrugations. Manufacturer says - your problem mate. The fix is to replumb with a deareator etc to try to get rid of the air. So given we lose a bit on using the diverter rather than the ASHP, we have some way to go before it cancels out the cost of the replumbing - I'd also add a heat meter and the kit to be able to monitor the CoP, so it's not a cheap solution fix - and it may not work!

Could do that and tbh, in the summer the tank is hot to overflowing with all the solar divert. I'd just have to remember to go back to heating only before the winter. Although at ambient it wouldn't come on anyway...

@Wil @MikeSharp01 @alfaTom Looks like you all have been through the CE MCS scheme and self installed. I'm assuming that when the unit arrived, there was some detail on what connections to make between the indoor Carel user interface and the ASHP itself. I've worked out which additional connections can be used to switch between Heating and Cooling but can't work out how to turn off Hot Water. So wondered if the connection instructions you received had this info?

DI-6 works the same way as DI-4. So connecting to GND (8) sets the unit in 'Hot Water + Cooling/Heating' depending on which one is connected. Given we don't use the Hot Water modes, only Cooling or Heating, I'm going to have to find out how to switch off Hot Water....

Good question. I've redone the experiment swapping from heating to cooling and when I look in the app to set things back to heating, it shows the unit as being in cooling + DHW. So it looks as though connecting DI-4 to ground hasn't set the unit to just cooling, it's set it to cooling +DHW. Which means, I'll have to find out how to turn off DHW as we only use the unit for heating and cooling..... I'll attach another wire to the DI-6 for setting things back to heating to see what happens. Can't see anything on the schematics for DHW - although the schematics are very blurry, so it's hard to tell.

You'll have to connect DI-6 to common to put the unit back in heating mode. DI-4 and DI-6 are latches, so making the contact and breaking it doesn't return the unit to the previous mode. I'm going to build something in parallel to the thermostats which when activated will run cooling at night on the cheap rate. I'll also have a boost button for, say, 3 hours for when we need additional cooling during the day. Will also make it accessible through Google Home, so if we're away for a long time, I can turn it on remotely.

@HughF Interesting - it works as a latch. (Probably should have expected this thinking about it). So when you connect DI-4 to GND, the unit switches from heating to cooling. But when you disconnect it, it stays on cooling, so you'd have to connect DI-3 to GND to get it to switch back to heating, or do that on the controller or app. With a suitable relay, you could switch to cooling and then drop back to heating but you'd need 3 wires. Simon

@HughF thanks - there's a spare pair on the cat 5 into the house, so I'll rig that up with a switch in the house to see what it does. Simon

@HughF I'm assuming that these connections override whatever may be programmed on the internal Carel controller (and the app)? So you could leave the controller/app on Heating but have a relay make the connection between DI-common and DI-4 and the unit would switch to Cooling mode. Obvs, I'd need to also provide switched live to the 4 zones on our Heatmiser UH4 wiring centre to open the valves on the manifold and give the ASHP the boiler enable signal. In our case, we'd have to replicate the programming for when the cooling comes on which is currently in the thermostats but that's pretty easy to sort out. We normally run the ASHP at night on off peak.

Thanks @HughF Like Mike, I'd ignored that page because it was headed 3-phase unit and we've a single phase unit - next time I speak to them, I'll point this out. Simon

Apologies if so - I did a search before posting but didn't see anything

Thanks @JohnMo - I'd had a look at these a while ago. Looks though as if you have to switch modes manually as opposed to based on the temperature? If I can find a way to automatically switch the Cool Energy unit from heating to cooling, then I think I'll end up using some Open Energy Monitor emonTH units as thermostats, sending data to a Pi with the eMon software and then sending signals to something like a Sonoff 4 switch gizmo, to control the call for heat on the 3 zones and to manage the ASHP. But if I can't find a connector on the ASHP unit, then I'll have to start writing down how to make cooling happen so that when I'm gone someone else can program it. Simon

Agree and it's an option but the thermostats do manage when the ASHP is running - we only heat the slab at night on cheap rate. And there's a downstairs bedroom which needs less heat than the rest of the house, so we do need some zoning....

Hi, We have a Cool Energy ASHP - it's doing sterling work during the heat waves at cooling our insulated slab, however.... To make this work, we have to set the unit to cooling on the internal display/control unit, then whack the thermostats up to their maximum to trick the system into actually running. So the call for heat gets the unit running and opens the manifold valves. There are a couple of issues with this. Firstly our thermostats highest setting is 25C, so if it's hotter than that, then the trick doesn't work (we can live with this by making sure we get the cooling running before things get too hot. The second, is that in an ideal world we would use thermostats that could generate a heating or cooling signal depending on the temperature and use this to switch the ASHP between heating and cooling. We could do this if there was a connection on the outside unit that controlled heating/cooling mode. Does anyone know if there is such a conncetion, we can't see one from the schematics in the manual. Or has anyone managed to sort this out in some other way? @dpmiller any thoughts? Simon

No but they do get you top of the class in other respects. To date this year our energy provider owes us about £5. All electric, almost passive house, PV, MVHR, ASHP and batteries. Our EPC is A with a 100 score, which I think we could get higher by getting them to use a more recent EPC version. But it's crazy that all the technology that makes for a comfortable energy efficient home isn't properly taken into account in the EPC/SAP system....

I'm pretty sure we have the same blinds and there's no flapping. They are much more robust than internal venetians. It's blowing maybe force 4 or 5 here at the moment and there's no movement. You can connect a wind sensor that will retract the blinds when it hits gale force 7 or whatever - we've turned ours off though, so the blinds have managed everything the weather has thrown at them for the last 3 years.

Talk to Hallmark Blinds - I can't remember what ours cost but it wasn't prohibitive. And you don't need anything fancy for the 'cassette' that the blinds park into when up. All you need is a properly sized gap behind the cladding, so that the blinds can be fitted into the gap.

+1 for that - we also have external blinds on the south facing windows and no curtains. Make sure you build in cassettes for them to go up into. We also have overhangs on the ground floor windows but with the blinds in their horizontal position, we find that they let in the sun from the autumn through to spring which is when you want the solar gain and for the summer months, with the sun higher, they don't let any sun, so no solar gain. You can see this on our architects web site -> https://lhc.net/projects/ashcroft-creating-a-low-energy-family-home/. In this photo, the blinds on the 1st floor bedroom are up, the blinds on the ground floor are in their horizontal setting.