I don't see major problem! It isn't as if the flow/return temps get to 50℃ in a few mins, which would indicate the primary circuit is struggling to give off heat to the cylinder. Takes about 40mins. The super-close flow/return temps are just a function of a very efficient heat exchanger giving off enough power at low Δt.Ronski wrote: ↑Tue May 06, 2025 9:06 pm I've repurposed the old Shelly sensors off my boiler on to the primary flow and return, just to see what's going on.
It doesn't quite make sense, below is a hot water heating cycle, now I would expect some more separation in the flow and return temperatures when heating the tank. but there isn't really any and its completely different to Joe's hot water cycle.
Any thoughts?
I know it's only crude with the temperature sensors tucked in behind the insulation on the pipework in the utility room, but it's just odd how flow & return stays the same for almost an hour then the big seperation. We have lovely hot water so its clearly working.
Edit: To add the heat pump was only drawing power between 21:31 and 22:22, it then drops back to about 5w
Starting out on my heat pump journey
Re: Starting out on my heat pump journey
12x 340W JA Solar panels (4.08kWp)
3x 380W JA Solar panels (1.14kWp)
6x 2.4kWh Pylontech batteries (14.4kWh)
LuxPower inverter/charger
(Artist formally known as ******, well it should be obvious enough to those for whom such things are important.)
3x 380W JA Solar panels (1.14kWp)
6x 2.4kWh Pylontech batteries (14.4kWh)
LuxPower inverter/charger
(Artist formally known as ******, well it should be obvious enough to those for whom such things are important.)
Re: Starting out on my heat pump journey
Thanks, just seemed odd, you'd expect the return to be cooler as it's passed some heat into the tank.
I did a little Googling earlier, and that suggested Vaillant don't alter the flow rate.
Like I say, we've got nice hot water, and that's costing about 18p a day, which is less than the gas standing charge.
I did a little Googling earlier, and that suggested Vaillant don't alter the flow rate.
Like I say, we've got nice hot water, and that's costing about 18p a day, which is less than the gas standing charge.
Re: Starting out on my heat pump journey
All good!Ronski wrote: ↑Wed May 07, 2025 1:28 pm Thanks, just seemed odd, you'd expect the return to be cooler as it's passed some heat into the tank.
I did a little Googling earlier, and that suggested Vaillant don't alter the flow rate.
Like I say, we've got nice hot water, and that's costing about 18p a day, which is less than the gas standing charge.
Some parts of all this aren't immediately obvious! It takes big fat pipes shifting a lot of water and an efficient heat exchanger, but you can transfer a lot of energy with a very small Δt. And doing so is exceptionally efficient.
12x 340W JA Solar panels (4.08kWp)
3x 380W JA Solar panels (1.14kWp)
6x 2.4kWh Pylontech batteries (14.4kWh)
LuxPower inverter/charger
(Artist formally known as ******, well it should be obvious enough to those for whom such things are important.)
3x 380W JA Solar panels (1.14kWp)
6x 2.4kWh Pylontech batteries (14.4kWh)
LuxPower inverter/charger
(Artist formally known as ******, well it should be obvious enough to those for whom such things are important.)
Re: Starting out on my heat pump journey
I've now removed the boiler flue, which has the added bonus that it no long shades two solar panels.
Gas meter being removed next Friday.
https://postimg.cc/gallery/VPfqJPp6





Gas meter being removed next Friday.
https://postimg.cc/gallery/VPfqJPp6





Re: Starting out on my heat pump journey
Another panel going up there?
12x 340W JA Solar panels (4.08kWp)
3x 380W JA Solar panels (1.14kWp)
6x 2.4kWh Pylontech batteries (14.4kWh)
LuxPower inverter/charger
(Artist formally known as ******, well it should be obvious enough to those for whom such things are important.)
3x 380W JA Solar panels (1.14kWp)
6x 2.4kWh Pylontech batteries (14.4kWh)
LuxPower inverter/charger
(Artist formally known as ******, well it should be obvious enough to those for whom such things are important.)
Re: Starting out on my heat pump journey
Well done!
"Gas meter being removed next Friday."
"Gas meter being removed next Friday."
15kW PV SE, VI, HM, EN
42kWh LFPO4 storage
73kWh V2H EV
7kW ASHP
200ltr HWT.
3G
Deep insulation, air leak ct'd home
WBSx2
Low energy bulbs
Veg patches & fruit
42kWh LFPO4 storage
73kWh V2H EV
7kW ASHP
200ltr HWT.
3G
Deep insulation, air leak ct'd home
WBSx2
Low energy bulbs
Veg patches & fruit
Re: Starting out on my heat pump journey
Be careful on that ladder.... 

Re: Starting out on my heat pump journey
If you look closely, he does have the ladder strapped back to an anchor point.
19.6kW PV > 114MWh generated
Ripple 6.6kW Wind + 4.5kW PV > 34MWh generated
7 Other RE Coop's
105kWh EV storage
90kWh Home battery storage
40kWh Thermal storage
GSHP + A2A HP's
Rain water use > 530 m3
Ripple 6.6kW Wind + 4.5kW PV > 34MWh generated
7 Other RE Coop's
105kWh EV storage
90kWh Home battery storage
40kWh Thermal storage
GSHP + A2A HP's
Rain water use > 530 m3
Re: Starting out on my heat pump journey
Plenty of room, but it's a 2015 FITS SolarEdge system, and I can't be bothered with the hassle and cost of upgrading it, I would get a very nice boost if I upgraded it all as panels are currently 250w, but with a total of 15.5 kWp with the other systems I'll have generated 80 kWh by the time the days out. Although it would help in the winter.
https://pvoutput.org/intraday.jsp?id=10 ... t=20250510
As mentioned above it is strapped down, I use the same ladder to get on the main roof, but I secure it in the corner for that. I have two stainless steel eye bolts resin bonded into the wall, and use a ratchet strap to hold it very securely in place. The above shot wasn't in the corner, and the strap was at an angle, but it was secure. I put a block of wood in the gutter, so the gutter doesn't collapse either.
Re: Starting out on my heat pump journey
I’m off up onto the roof later today as we have 4 missing slates all in difficult positions on four different sections of roof. Fitted the roof hooks to the ladder last night ready - just got to work slowly and steadily as I have lost my head for heights over the years.
Only going to staple them back in with lead strips as a new roof is required at some point in the not so distant future.
At least it’s a calm sunny day again !
Moxi
Only going to staple them back in with lead strips as a new roof is required at some point in the not so distant future.
At least it’s a calm sunny day again !
Moxi