Air Source Heat Pumps

Th02msn

RichardC

The forum will not allow a new user to post links for some unknown reason but if you type in ‘grant air source heat pump manual’ into google then select the second listing titled ‘Downloads Grant UK’ then select the 7th option on the list titled ‘Air source heat pumps and accessories’ then select ‘installer and user instructions’ from there it is the first one on menu.

That then displays the manual.

Hope this works with you.

Thanks

richardc1983

OK I will take a look. If your individual room stats are not programmable how are you currently controlling the system for on off periods?

I imagine the rooms have thermostats like radiators have trvs which control the temp of the room? However there should be a main controller somewhere which governs the main overall temp.

The fact you have underfloor is even more important to leave on 24 7 but with slightly lower temps when In bed etc

Th02msn

Each room has a digital stat. Kitchen/sitting area set at 20 and bedroom set at 19. Hallway set at 18. All spare rooms, study and bathroom that we hardly use are set at 15.

I dont have ‘on/off periods’ at moment as the switch for CH and HW is left at ‘ON’ 24/7. Thats what was advised by our installer.

There is a separate control box for the ASHP but I have not touched any settings on it as I dont know what im doing.

richardc1983

So you control the heat pump parameters from inside the heat pump on the ATC controller this is where max flow temp will be set.

There is a separate temperature sensor display which is similar to your old fashioned room stats, you then have local control of rooms using their own zone thermostats. Obviously if the main thermostat was set at 18 and it was reading 19c and one of the rooms someone turned their local zone controller to 22c the heating would be off as the main thermostat governs the temp.

Your hot water cyclinder needs to be set between 45 and 50c whatever your most comfortable although if it'd just for washing and bathing 45c is more than ample for washing up 50c would be more suitable. Hence why dishwashers are good here.

You want to be on page 35 (setting the atc parameters) manual then page 37 for commissioning table and options. Page 35 tells you how to access the settings and options.

Advise what parameter 1 is set to it should be 40c for underfloor heating default is 55c so may not have been changed. Try it at 40c if the house is still warm and cosy then knock it down to 35c and see how u get on every house is different. Can you also tell me what parameter 14 is set at?

For the next setting I need to know the model number of unit you have. Also the electric immersion only needs to come on once per week to increase the cylinder temp to prevent legionella not once per day for an hour. This is set from the inside BTC controller so we will look at this separately once we do the first lot of settings in bold.

richardc1983

Looks like you can also change some of the settings from the indoor controller in page 40 and this would probably be better as this is the design of the system rather than just limiting the max flow temp outdoors.

Th02msn

Ok. I will have a look into that and let you know.

Can you just explain what moving the temp from 40 down to 35 actually does??

richardc1983

Th02msn wrote: »

Ok. I will have a look into that and let you know.

Can you just explain what moving the temp from 40 down to 35 actually does??

Standsrd gas boilers work on a flow temp of 70 to 80c meaning the water going through your radiators is that temp.

Underfloor heating is a bigger surface area so works on lower flow temps. So changing the flow temp means your limiting the maximum temperature the water going round the system is. The lower it is without compromising the comfort of the house the more efficient it is and cheaper to run.

matelodave

Richard is doing a good job so I'll sit and watch rather than put my oar in and confuse the issue

richardc1983

richardc1983 wrote: »

Standsrd gas boilers work on a flow temp of 70 to 80c meaning the water going through your radiators is that temp.

Underfloor heating is a bigger surface area so works on lower flow temps. So changing the flow temp means your limiting the maximum temperature the water going round the system is. The lower it is without compromising the comfort of the house the more efficient it is and cheaper to run.

One way to look at it is to fill a bath with 70c water to then cool it down with cold water so it's a, a comfortable 40c is wasteful if you can be comfortable and fill all your bath with water at 40c in the first place.

richardc1983

matelodave wrote: »

Richard is doing a good job so I'll sit and watch rather than put my oar in and confuse the issue

Of course Dave your input is most welcome and the more info the better. Can't believe these things are never setup properly.