GSHP Sizing

[nudgerreturns]

For those interested, my HP readings from one pump are:

Heat is set at 5. However the heat slope on the step controller is at 6.

MENU 3: GT1 - OFF 60.2 NOW 34.5

GT2 -27.2


Went into service mode to get the following:


GT6 Compressor 78.6


timer in menu 6: DHW Peak timer reads 0h 0m 0s
Add. heat timer reads 0h 4m 26s counting down.


7.1 = 3192 Heat pump HOURS

7.2 = 100% RAD 0% DHW

7.3 ADD HEAT HOURS 1110

 

[doitall]

It certainly seems they got it wrong thats for sure.

In my opinion all heat pumps should have a back-up ashp perhaps more so.

How many trenches did you end up with. ?

What was the design temperature. ?

Do you know what chemical and % they used in the loops. ?

I think you need to get the bossman onsite and thrash out their spec with what has been installed, it doesn't add up in my book.

is there an immersion heater for the hot water.

 

[snb]

there is a problem with the setup if the GT2 reading is minus 27.

this is the outside temp probe reading.

if this is correct then the sensor is broken or connected wrongly


GT10 is the temp of the fluid coming from the ground loops normally about 2 or 3

GT11 is the temp of the fluid going in to the ground loops and is normally about 0.

if these figures are lower then the ground loops are under sized

GT 1 reading of 34 would be about right for the underloor but they have set max temp to 60 which is too high for the underfloor unless it had a tmv fitted.

try turning the underfloor pump off for a couple of hours and see what happens to the rad temps and GT 1. this should start to rise quite quickly.

 

[SimonH2]

try turning the underfloor pump off for a couple of hours and see what happens to the rad temps and GT 1. this should start to rise quite quickly.

Does he also need to shut a valve to prevent flow round the UFH - if there is flow from the other pumps (quite likely) then he could quickly have "rather hot" water in part of the UFH.

Also, and this has only just occurred to me ...
He's talking of two pumps. I wonder if they've configured one to run the UFH only, and the other to run the rad and DHW. That would sort-of make sense as the setpoints could be quite different for the two systems - though it would also mean you can't borrow excess capacity if the two systems aren't sized right. It might also explain why the UFH is running fine but the rads aren't (probably using most of the heat to try and make DHW).

 

[nudgerreturns]

That's interesting thank you.

GT 10 is 3.4
GT 11 0.0

So by that would you be able to be sure the ground loops are OK? Or is that just an observation?


Not sure if I have a TMV, nor where my U/F pump is....

News from installer is that they now know I am contacting MCS with a view to complaint - and have promised a call tomorrow am to start making things right. So we shall see what happens. Thank you once again,

 

[Agile]

I did not even know that MCS had any complaints procedure for customers to use! Useful to know!

 

[doitall]

Would also be interesting to know how the two pumps are connected, and whether they share the same 400m of collector pipes, or 200m each.

 

[Agile]

Just pop round John then you can SeeItAll

 

[doitall]

Just pop round John then you can SeeItAll

Would love to turn up when the installers are on site.

I'm happily retired and it's gonna stay that way, got a meeting tomorrow night anyway.