@derek-m  Hi Derek, temperature sensor on Grant tank is at the bottom fyi.

Regarding the flowrate temperature being set at 35c it seemed to be OK a few days ago but lifted it to 35.5c as MIL was coming and it was tbh too warm for us at 21-22c.

It's our first year with it set on WC as it was set full throttle at 50c prior to my visit of an EHG. Now we just leave all the thermostats alone with no programs and just look at them to tell us the temperature and no more. The rest we control the WC on the Grant Controller. Seems an easier way but just not 100% convinced yet.

Posted by: @roamingbull

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@derek-m  Hi Derek, temperature sensor on Grant tank is at the bottom fyi.

Regarding the flowrate temperature being set at 35c it seemed to be OK a few days ago but lifted it to 35.5c as MIL was coming and it was tbh too warm for us at 21-22c.

It's our first year with it set on WC as it was set full throttle at 50c prior to my visit of an EHG. Now we just leave all the thermostats alone with no programs and just look at them to tell us the temperature and no more. The rest we control the WC on the Grant Controller. Seems an easier way but just not 100% convinced yet.

It may have been adequate a few days ago, when the OAT was higher, but now 35.5C could be inadequate.

Your system cannot be operating in WC mode if you can change the LWT setting.

Posted by: @allyfish

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@roamingbull You running on weather compensation? If the house is too cold when it's milder and warmer outside you may need to flatten the WC curve a little and increase your minimum flow temperature. Customising the WC is trial and error as every house is different and how your heating responds is influenced by UFH vs rads or combination and how long each day it's switched on for, etc. 24/7 would give chance of the most stable control of course, but I find that's a little too warm for us overnight. Check these parameters for settings, values are the defaults:

2102 Maximum Water Temp °C 45 (default by Grant, set to 35°C for your system?)

2103 Minimum Water Temp °C 30 (don't set too low, for UFH +wet rad combined this is probably about right)

2104 Minimum Ambient Temp °C -4 (I was advised by Grant commissioning engineer to raise this to 0, which works for me)

2105 Maximum Ambient Temp °C 20 (above this value your heating will be disabled)

-- Attachment is not available --

Hi Derek, I have set it up as above bar 2102 is at 35c. 

2101 can’t see what this should be at from Ally’s posts. Anyway ours is set too 35c?

2100 is set to 1 which apparently means WC is on from an early post of AF  

I was told only to play with 2102? 

I don’t play with room thermostats  

its UFH throughout concrete floor downstairs and engineered wood upstairs  

Any suggestions are thoroughly appreciated as it drives me up the wall  

(hope you don't me chiming in here @derek-m as a fellow Grant owner) @roamingbull, check 2100 is set to 1, and as a default I would set 2101 to 45degC. If 2100 is set to 1 and WC is enabled, the setting in 2101 should be disregarded, but I just wonder whether your setting of 2101 at 35degC means it is overriding the setting of 2102 'maximum outgoing water temperature' and preventing 2102 being adjusted to a higher LWT.

Good Morning AF & D,

2100 is set to 1.

2101 = Now just set to 45c as you stated.

2102 = 35c This was the one the HG told me to only adjust FYI. 

2103 = 30c 

2104 = 0 not the -4 

The EHG more or less told me to control this way but he was very Daikin orientated but well worthy of his visit as he straight away noticed that WC wasn't activated and it was set at 50c.

Since his visit the ashp is very quiet instead of previously running at full throttle so to speak. The fan just blows over if you know what I mean.

So as you know the settings we have what is the most efficient way to run our ashp please? Without too much messing. Like I stated I want a system after nearly 3 years to be less of a headache and cheapest as possible to heat our home

Ally will see how we get on with the hot water now at actually 55c!!!

We don't like the house that hot tbh but know if we have visitors we don't want it cold. It does seem to react quite quickly.

Posted by: @roamingbull

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2102 = 35c This was the one the HG told me to only adjust FYI. 

Yup, 2102 is the main parameter you need to adjust, if you find the house not keeping temperature as the outdoor temperature lowers, then raise 2102 by a few degrees and see how it gets on. It's the maximum LWT at the minimum air temp, 0degC in your case, so for air temperatures above 0degC your LWT will decrease. When the ASHP is regularly defrosting you may find the LWT is often below target temperature, that's unavoidable with the defrost method most ASHPs currently use.

@allyfish So now I have the setting's I have quoted the only thing I need to adjust in the future is 2102?

And this in turn will run my ashp at best efficiency, Knowing that the lower the flowrate temp is the cheaper the ashp will be the other parameters don't matter for the effiency side?

Since I change the settings the house has warmed up. To the point I'm going to have to drop the 35c!! It's now sat at 22.5c fyi

Little spread sheet to play with here

, you can change your 2102 max LWT and 2103 min LWT parameter settings in this and see what it does. It shows you what the LWT is at different outdoor ambient air temperatures. You only have 5degC between min and max at the moment, which isn't much. You might not need any more, it's a trial and error process getting the 'curve' (actually a flat line for GRANT ASHP) to match your house. 

@allyfish Thank you.

Just as a note as I read back through previous posts, We have UFH throughout including upstairs with no rads!!

What I changed early has made the floor warm. Thermostats have shut off at 23c. best crack the shorts out and hopefully the wallet doesn't suffer.

Posted by: @roamingbull

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Posted by: @allyfish

↑

@roamingbull You running on weather compensation? If the house is too cold when it's milder and warmer outside you may need to flatten the WC curve a little and increase your minimum flow temperature. Customising the WC is trial and error as every house is different and how your heating responds is influenced by UFH vs rads or combination and how long each day it's switched on for, etc. 24/7 would give chance of the most stable control of course, but I find that's a little too warm for us overnight. Check these parameters for settings, values are the defaults:

2102 Maximum Water Temp °C 45 (default by Grant, set to 35°C for your system?)

2103 Minimum Water Temp °C 30 (don't set too low, for UFH +wet rad combined this is probably about right)

2104 Minimum Ambient Temp °C -4 (I was advised by Grant commissioning engineer to raise this to 0, which works for me)

2105 Maximum Ambient Temp °C 20 (above this value your heating will be disabled)

-- Attachment is not available --

Hi Derek, I have set it up as above bar 2102 is at 35c. 

2101 can’t see what this should be at from Ally’s posts. Anyway ours is set too 35c?

2100 is set to 1 which apparently means WC is on from an early post of AF  

I was told only to play with 2102? 

I don’t play with room thermostats  

its UFH throughout concrete floor downstairs and engineered wood upstairs  

Any suggestions are thoroughly appreciated as it drives me up the wall  

 

 

 

If I am understanding correctly, your WC curve is set to LWT of 35C @ OAT of -4C and LWT of 30C @ OAT of 20C. So at an OAT of 0C, the LWT should be in the region of 34.17C, and at an OAT of 5C, the LWT should be around 33.13C. I therefore suspect that the slope of your WC curve is too shallow.

Try increasing the setting of 2102 from 35C to 40C. This should keep the IAT from falling from the desired value when the OAT reduces. You may have to adjust 2102 in the future to fine tune the WC to match the heat loss of your home.

What are the settings on your room thermostats, are they starting and stopping your heat pump?

@derek-m Hi Derek I just set it up as per Ally's post.

Bar that the 2102 is at 35c. This was what my EHG told me to only adjust.

I changed the settings this morning as per AF's email. TBH the floor heated up quite quick and actually far too warm now.

As you can tell I've minimal experience with the ashp. Tbh honest with our busy lives and that I work away most of the year I just want a system that I don't have to constantly think about and that it's running at maximum efficiency. 

The thermostats are set to 23c. But I was hoping I could fine tune it that I could see approx 21c maximum on those thermostats.

Posted by: @roamingbull

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@allyfish Thank you.

Just as a note as I read back through previous posts, We have UFH throughout including upstairs with no rads!!

What I changed early has made the floor warm. Thermostats have shut off at 23c. best crack the shorts out and hopefully the wallet doesn't suffer.

 

 

Just a note of caution. Correctly optimising the WC curve can literally take weeks to achieve dependent upon variations in weather conditions.

Only one of the four adjustment parameters should be adjusted at any time and then its effect observed over a day or longer if necessary.

When the OAT is below +5C, make adjustments to parameters 2102 or 2104, and when the OAT is above +5C, make adjustments to parameters 2103 or 2105.

If you get OAT's below 0C, I would suggest setting 2104 to -5C, otherwise the IAT may start to reduce when the OAT falls below 0C.

If the IAT starts to fall when the OAT goes below +5C, then increase 2102 by 1C and wait for IAT to stabilise, which could take quite a number of hours. Obviously lower 2102 by 1C if IAT starts to increase.

At OAT's above +5C adjustments should be made to 2103 and possibly 2105.

If the IAT is increasing when OAT is above +5C, then reduce 2103 to say 25C. Then carry out the fine tuning adjustments as described above.

Because you have UFH throughout, expect reaction times to be slower.

To help prevent IAT from going too high, it may be advisable to set your room thermostats at 1C above desired temperature. This should help prevent IAT from going too high but may probably cause the heat pump to cycle. This is perfectly normal provided that the cycling is less than 6 times per hour.