Ground Source Heat Pumps

beardymarrow

poohbear59 said:

Thank you for your help. I forgot that most people wouldn't be able to get this far on the settings.

1.3
Out 20° Curve 20.0°
Out 15° Curve 24°

1.11
2

2.3
DHW is 50°

I called a local guy who knows about Legionella. He is coming later to take a look at what he thinks we need here for customers.

Cheers. Can you get me the rest from 1.3. Just scroll down.

beardymarrow

poohbear59 said:

Where will I find the temperature that I set for the hot water peak please? I'm going round in circles looking for it.

You don't set the temp. It's increased by 5 degrees from the peak. So, that is 5 degrees above the DHW stop temp (DHW stop temp is the DHW set temp plus half the DHW hysteresis which is usually 5 degrees). In your case therefore that would be 57.5degreesC.
Edit: This is actually for the additional hot water, not for the peak. My bad.

poohbear59

Out 15 curve 24
Out 10 curve 28
Out 5 curve 32
Out 0 curve 36
Out -5 curve 40
Out -10; curve 44
-15    48
-20.   52
-25   56
-30  60
-35.  64

Patrol

poohbear59 said:

Where will I find the temperature that I set for the hot water peak please? I'm going round in circles looking for it.

I looked at this a long time ago and concluded it could not be set. If you happen to be around when it is running you will see a stop temperature of 65c when you press the Info button. This post and the three below it refer but I no longer have the PDF that lovesgshp provided so cannot provide detail on that

https://forums.moneysavingexpert.com/discussion/comment/65471863#Comment_65471863

Patrol

poohbear59 said:

It is a holiday let and if I get it warm enough for people downstairs the bedrooms are too hot.  

Was this always the case or has some helpful guest fully opened radiator valves upstairs and unbalanced the system. In which case yes thermostats may well make it clearer when it has been changed in future.

Patrol

@poohbear59
Looking back at the last couple of pages it would be helpful for you to provide more detail while you have access to the property, as this could lead to more targeted questions. Something like the below where n is a number:

2.1 0h
2.2 nd
2.3 50

4.1 all show off
4.2 all lower case
4.3 all show off

5.2 2/3
5.4 normal

7.1 nnnnn
7.2 23% DHW 77% RAD
7.3 nnn
7.4 nn% DHW nn% RAD

8.1 60

& in my previous response I mentioned thermostatically controlled radiators as a response, I have a recollection that this type of control may not be recommended for heat pumps as they are expected to have something like 70%+ flow rate at all times.

poohbear59

Thank you Patrol the link you provided was very helpful. I've had the water treatment specialist here and he had given me lots of information about the necessary temperatures and internals for peak temp. He says as it is occupied year round I don't need to increase temperature every day and keeping it at 50 is okay so long as we increase temperature and run the system through of it has been empty. I think I will do it once a week, instead of the peak temp every single day. It should save us some money. 

I am pretty sure that some  helpful guest has opened up the valves fully. I'll check and see if I can partly close them. They often shut them off completely.  We were too hot last night. It is useful l staying in here as we are learning a lot. We have had the system for 11 years and it is the first time we've tried it out for ourselves. We have blocked it off, and it can't be booked, so that we can test it ourselves and to see what we can do to improve things.

I have to say I am not very warm in the living room today. We have vaulted ceilings and open plan kitchen/living room. 

2.1 0h
2.2 it was daily. I've just changed it to one day.

4.1 all on 00.00-00.00
4.1.1   is 0
4.2 all on 00.00-00.00
4.3 as 4.2
5.2 2/3
5.4 normal only add heat

7.1 30052h
7.2 23% DHW 77% rad

7.3 471h
I don't have a 7.4
8.120 mins.
It is cold here today. We are 1300 feet above sea level in the North Pennines.

beardymarrow

Patrol said:

poohbear59 said:

Where will I find the temperature that I set for the hot water peak please? I'm going round in circles looking for it.

I looked at this a long time ago and concluded it could not be set. If you happen to be around when it is running you will see a stop temperature of 65c when you press the Info button. This post and the three below it refer but I no longer have the PDF that lovesgshp provided so cannot provide detail on that

https://forums.moneysavingexpert.com/discussion/comment/65471863#Comment_65471863

You're right, it is 65deg, not +5deg (I was thinking of additional DHW, not peak DHW). I've corrected my post above.

Here is the pdf referred. https://u.pcloud.link/publink/show?code=XZvgFVVZ2chaVqGMrUFyichlWJSMHQbsQoMk

beardymarrow

Patrol said:

...

& in my previous response I mentioned thermostatically controlled radiators as a response, I have a recollection that this type of control may not be recommended for heat pumps as they are expected to have something like 70%+ flow rate at all times.

70% if you don't have a bypass, reduced by 40% if you do (which I assume means down to 60% nominal flow). The manual is here and has loads of useful info on this - https://u.pcloud.link/publink/show?code=XZCjGYXZPcHhhW7eRNR8qHTFFgu8fSh3Y86X - Page 54.

Patrol

Thanks for your figures, I can't see anything that looks terrible. In my non-expert view;

• For 2.2 I would expect it to be 7d if you wanted to increase the temperature once a week
• 4's and 5's look OK I think
• 8 being 120 minutes looks fine. Mine was set to 60 at installation and I changed to 180. If you see additional heat being used 2 hours after the pump starts a cycle you could consider increasing it. Do you know if your unit runs for longer than 2 hours at a time?

7.3
471 hours over 11 years is about 0.8 hours a week additional heat. Each hour (at 5.5's 2/3 setting) uses 6kW of electricity. Reducing the water peak frequency should reduce additional heat a bit.

7.1 + 7.2
The manual suggests a heat curve of 4 to 6.5 for a property with radiators, you have a setting of 5 which seems reasonable but the property is cold downstairs and hot upstairs. I'd probably check the downstairs radiators are fully open and those upstairs are slightly closed and tweak a bit each day until happy or until you can get thermostat controls. If downstairs is still too cold you could increase the heat curve to 6 but generally speaking this will increase the running cost. At that point if the house has never been warm enough you might want to check if there are enough suitably sized radiators downstairs.