Caernarfon 18kW ASHP review

[Benjseb]

Also, on hot water we’ve played around with timing it vs leaving on

 

When timing it didn’t work very well with extra baths. Because it wasn’t timed to go on again until later the 3rd bath was cold

 

We switched to continuous which fixed this but used more energy. I then set the delta lower, so it waits for an 8c drop in tank temp before triggering. As such it will trigger if someone has a bath or shower. It not if just washing hands or doing the dishes. 
 

we’ve actually got out temp set to 46c now and it seems piping hot. The sensor is 1/3 up the tank so obviously the water were getting is hotter than 46 initially. 
 

overall that’s now cost effective and we always get warm baths. 

[joe90]

I have two thermostats on my DHW tank and I use the upper one for the two of us and switch it to the lower one (greater capacity of DHW ) when we have guests, it’s worked so far.

[H F]

Benjseb, the similarities are crazy. Thank you for sharing your insights. I’m going to fiddle with the valves - are they 1/4 open on the incoming or exit valves?

[Benjseb]

11 minutes ago, Home Farm said:

Benjseb, the similarities are crazy. Thank you for sharing your insights. I’m going to fiddle with the valves - are they 1/4 open on the incoming or exit valves?

we had TRV on one end then closed off the other. Started at 1/8 turn (some still like that) but turned to 1/4 turn if not warm enough

 

yours may need different depending upon how they are piped. 
 

It does show how much difference UFH makes. So thankful we decided to lay that when changing the floor, despite going with an expensive retro fit solution due to ceiling height. 
 

I’d say if we put UFH in the lounge, we could run the flow temp at 35-40 all year round as the rads in the bedrooms are set to 18c for optimal sleep health. 

[Benjseb]

@Home Farm Someyhing that may interest you...

 

Did you say you set back temps overnight? I’ve been experimenting with ours. We had a 1.5c setback overnight in all rooms. Last few days I’ve removed this (so now all rooms are either 18.5 or 19.5 all day)

 

since doing this I’ve managed to reduce the flow temp 3c from the norm (so yesterday ran at 39c). This is because the lower flow temp is fine to maintain the room temp but can’t boost it up to recover after the set back

 

I’ll do this for a few more days To allow for weather fluctuations but initially it seems we’ve saved about 10kWh per day using the lower temp and higher overnight room temps. 

[H F]

Thanks again for sharing. I’ve torn my knee cartridge so out of action for a few days. Will tamper with valves later this week.

[Ed Davies]

I did a similar experiment this time last year to see if running the oil boiler overnight rather than having it switched off from 23:00 to 07:00 increased the heating bill much. It did, but nothing like as much as you might expect from the 1.5 times as much running time. https://edavies.me.uk/2019/01/continuous/

[H F]

1 hour ago, Ed Davies said:

I did a similar experiment this time last year to see if running the oil boiler overnight rather than having it switched off from 23:00 to 07:00 increased the heating bill much. It did, but nothing like as much as you might expect from the 1.5 times as much running time. https://edavies.me.uk/2019/01/continuous/

 Very interesting piece Ed.