Anway similar situation in that I was on single phase not realising what transparent mentioned about the draw on electricity but have had no issues (from what I can gather it's never used more than 4kwh). The EV charger can take up to 7kwh but never does from the battery management. 

With some of these issues inmind I applied for 3 phase and gratefully had free installation from my DNO.... Which opened up another Pandora's box 🙄

I've just started running my pumps again in earnest following installation of a couple of magnacleans going to the pump after having a p1 fault and having to replace after finding sludge and filings.

I'm just about to put some more biocide and inhibitor in following a flush and hopefully should have a more efficient system but already looking at reducing the flow further as it running warmer with the milder weather at the moment.

Did you ever get your system running to your requirements?

the backup ports are for use with the optional gateway device which is for just that.   I specifically checked.  Gateway is extra as was labour to connect it.  

We decided we didn’t need that functionality for the extra cost.

it can always be added in later albeit more labour to add it in afterwards.

in the event of a power failure nothing will work, I know that.

I'm puzzled by that.

The Sig Energy datasheet indicates that there are two separate 240v power outputs.
The one marked "Backup" suggests that it should remain live during an outage.

You'll need to check with your electrician how he's utilised those two ports.

So I guess in my head I wanted to get them working given I paid to have them connected up and thus I’ve been thinking they needed to act out their full capabilities.

Thats the only logical explanation because for their main function they emphatically dont.

Perhaps though he never intended them to be immersion heaters simply add volume as you say.

Could be, then once he had received them he realised they had an extra function and thought that it would be best to enable it!

maybe the answer is simply then to leave their immersion heater aspect disabled permanently and just accept they are inactive volumisers. Could possibly even throw the power supply off to each of them to make sure of it!

It definitely is an option.  You can always put them on if something bad happens and you need them, at this point you wont mind paying the price.  

One more matter - You asked about the water pump mode for the heat pump.  On reflection Im not sure how effective sniffing mode will be given that both your heating loops can shut off completely.  You may need to experiment and watch.  

Another angle just occurred, given your heating loops can shut off completely, its just possible (although unlikely) that the only water available from a defrost cycle is the water in the volumiser.  In this case its also just possible (although unlikely) that the immersion heaters may be needed to complete defrost.  This is a situation you probably want to avoid.  

Grant and others take the opportunity of the existence of a tank to add a backup heater which performs a separate function.  Many volumiser tanks don't have one.

Heat pumps specify a minimum volume of water on the system and a volumiser tank is added if the system volume is less.  Because you have zone valves your system the available volume could be negligible if both valves close simultaneously.  That may be why you need the volumisers. 

It's quite likely your system would be better without the zone valves, heatmisers and volumisers, but without the hydraulic design I can't be definitive about that.  The second biggest mistake heat pump installers seem to make is adding unnecessary complexity (the biggest mistake is oversizing).

ok fair point but what’s confusing me, which I have not said, is that as soon as he had installed the tanks he came and apologised and said they needed their own power supply, which I had to pay the electrician to add in, much to my annoyance.  So I guess in my head I wanted to get them working given I paid to have them connected up and thus I’ve been thinking they needed to act out their full capabilities.

Perhaps though he never intended them to be immersion heaters simply add volume as you say.

I don’t think it’s an issue when both manifold completely shut down as the HEAT supply would be turned off then on the ASHP so no volume at all needed but potentially I guess only one small room could remain on with all others off, in which case the point is valid.  I guess the introduction of room stats made the system volume variable / unpredictable.

maybe the answer is simply then to leave their immersion heater aspect disabled permanently and just accept they are inactive volumisers. Could possibly even throw the power supply off to each of them to make sure of it!

I think I proved to myself over the last week the immersion feature seems to be a bad idea anyway even in very cold weather.

i still have no real idea why the plumber decided adding volumiser tanks was necessary. I’m going to quiz him tomorrow as powering them seems to cause several issues!

I still am not sure you get the point of volumiser tanks.  They add water volume to the system.  They don't need power.

Grant and others take the opportunity of the existence of a tank to add a backup heater which performs a separate function.  Many volumiser tanks don't have one.

Heat pumps specify a minimum volume of water on the system and a volumiser tank is added if the system volume is less.  Because you have zone valves your system the available volume could be negligible if both valves close simultaneously.  That may be why you need the volumisers. 

It's quite likely your system would be better without the zone valves, heatmisers and volumisers, but without the hydraulic design I can't be definitive about that.  The second biggest mistake heat pump installers seem to make is adding unnecessary complexity (the biggest mistake is oversizing).

You need to give some thought to those ufh loops, they can't be allowed to suck energy out during dhw cycle.  Removing the ufh pumps would be ideal but I don't know if the chofu water pump has sufficient power to do without them.  Presumably your plumber did the calculations and decided they were necessary?

will do, I’ve not made any changes today, I am gathering my thoughts on everything learn from here and the Chofu manual first but I will decide what to change in a day or so.

i think I mentioned before that the builder did the floor, screed UFH pipes and manifolds and spoke with the plumber who amended his ASHP design.  The issue discussed at the time was the impact a thermostat in each room would have, no mention of the manifolds having their own pumps being an issue.

i can realistically resolve the issue by dropping the room temp on each thermostat during DHW cycles so it is resolvable albeit somewhat of a kludge solution.  

With the HEAT loop valve closed there isn’t really too much scope for extracting heat out of the floor, it’s just going to loop it around so more of a case that it pauses putting additional heat in for two periods of 2.5hrs a day. Running the manifold pumps would be a waste of power though for sure.

i still have no real idea why the plumber decided adding volumiser tanks was necessary. I’m going to quiz him tomorrow as powering them seems to cause several issues!

Hi Transparent

diagram looks broadly correct I think.

1) in the event of a power failure nothing will work, I know that.  Sigenergy sell a seperate “gateway” device that gives uninterrupted power supply in the event of power cuts. We did not buy one of those.

2) anything can run off the batteries including solar export providing the total capacity on the inverter isn’t exceeded.  

Any excess beyond the inverter capacity or remaining battery life, just comes from the grid.  

In reality when on battery there’s always a delay from the CT clamp to inverter responding to changing loads and some is drawn from the mains as it ramps up to the new demand level.

In theory an owner could top up the batteries with off peak electricty then export it back later in a peak period but with the losses through the inverter each direction and factoring in the duty cycle life on the batteries it would be very unlikely to make sense.

Ooops - I have just re-read your reply and you said "wouldn't" advise... I mis-read that as "would"!!!!

Ok I will leave it as it is then and focus on the other setting changes, likely on the WC curve first, then after a couple of days try out the volumiser settings learnt from the Chofu manual as per my prior post!

Please post back on how you get on.

You need to give some thought to those ufh loops, they can't be allowed to suck energy out during dhw cycle.  Removing the ufh pumps would be ideal but I don't know if the chofu water pump has sufficient power to do without them.  Presumably your plumber did the calculations and decided they were necessary?