ashthekid

Yes, very hard water here. I have a water softener but obviously not used or hooked up to to this part of the system. I just pray this hasn’t spread to the heat pump itself.

A whole new home plumbing system that is less than 2yrs old and consists of UFH both upstairs and downstairs(and a few towel rails) onto a split system Hitachi Yutaki S ASHP. I had an issue with any heat flow going through to the UFH manifolds and then a leak from the low loss header. The leak looks like it was there for quite some time which would explain the pressure loss over a long period. Just had the loss header replaced and pump removed. This is what the pump looked like. What would cause such a state after so little time? That is not sludge inside, it is rock hard! No inhibitor? Miscalculated inhibitor, the leak, some kind of chemical reaction….?

To be totally honest I am probably running the ASHP as a traditional gas boiler in that I'm heating up the DHW tank from 5am to 10am and then again from approx 2-4pm, off for the peak times on the Agile tariff(4pm-7pm) and then back on for a couple of hours 7-9pm. UFH I having coming on at 5am pretty consistently all day until 11pm which is when I drop the temp down below 20 degrees. I don't have all zones on though. I would say on average I always have about 6 zones totally switched off and during the summer I didn't have any UFH switched on for the months of May/June/July/August. This is the 2023 data I took from my OVO account before switching over to Octopus's Agile tariff last week.

@JohnMo Yes it does sound bonkers but there lots of extra rooms like 2 offices, Tv room, playroom, utility, 2x lounges, snug, hallway, landing etc so it very quickly added up. It's a new build within 200yr old walls so quite an unusual setup. Running costs are a lot more than I calculated that's for sure and during the build all the energy costs were constantly creeping up. We only have electricity and over there last two years we have spent approx £700 per month during the winter months and this summer that came down to £200 per month, probably mainly due to the benefit of solar panels, albeit a small array(10 panels) which I wish I had made larger now of course. And I'm really annoyed now that I did not notice the LLH was not the intended Clum one that I had agreed to.

I was told it was kind of essential on a system as large as this to boost performance and efficiency whilst also balancing out the flow rate when there is more than one circuit. It definitely looks made up rather than off the shelf which I wish I'd identified before as the original quote from the plumbing company stated a Culm DN25 low loss header which I believe is a brand selling off the shelf units. So our only source of heat is with our Hitachi Yutaki S 8.0 split system ASHP which I was told could handle a peak load of 13.5kW ASHP. UFH throughout downstairs and upstairs via 4 manifolds (2 up and 2 down). 400l hot tank. 6 plumbed towel rails. This covering a 5 bedroom, 4 bathroom home. 19 thermostats covering approx 380sqm. We have a large open plan kitchen lounge dining area which has a glass wall and bifold on one side so I know we have some serious heatless from there as well as some big air gaps around some oak trusses which I know doesn't help. The whole house is run on electricity so no gas or oil.

Hi, I have a relatively new ASHP setup which is approx 2yrs old and at the beginning of last year I started noticing a drop in pressure which I was having to top up every month or so which didn’t bother me as I couldn’t see if there was a problem anywhere on the setup. I have since discovered a very small slow leak from the low loss header which would explain the pressure dropping and maybe why the whole heating system isn’t working as efficiently. I’m wondering what people’s thoughts are on this? Do I get it re-welded or replaced like for like(although I support it was built on site with the amount of welding I can see on it) or removed or replaced by a different setup? Here is a photo of it attached. I’ve just been quoted over £1000 for a replacement(labour 3hrs & parts) which I thought was quite punchy considering a LLH is only around the £200-350 price point.

My logic behind the set point for UFH being 43 was that if the DHW is set to 45 and thats what the ASHP is pushing for then i may well use that similar temp as the same amount of energy is going to be used to reach the higher temp anyway. Is it not sensible to just have them set at the exact same temp each?

Yeah the air gaps are definitely annoying and affecting the large open space room which has tall ceilings and the exposed trusses. That's the toughest room to heat by far and you could really feel it again last night with the temps that bit lower again.

@PhilT I believe it’s the new LCD controller on the Yatuki S model which also includes the integration with the Hi-Kumo app to control the system via WiFi. Well it turns out the reason why the UFH was off was this app had somehow switched it off and I bizarrely could not override it on the controller itself until I went back to this app. It’s a terrible app anyway with it being so basic you literally can only switch the system on or off. Since switching it back on I have UFH back. @sharpener Those are set temp points on the Home Screen. What temp do you suggest I set the UFH set temp too? I have adjusted it to 43 now as I’m noticing our bills are really starting to shoot up now the outdoor temps are dropping. I’ve been hitting £30 a day recently. And during those really cold nights when the ASHP struggles, is there a backup or addon that could be put in place for me to switch like you would an immersion heater on a hot water cylinder? @mike2016 suggested a Willis heater. This sounds like a good option.

It’s constantly saying Demand Off for some reason.