Will reply later in detail. Who’s the manufacturer?

@editor cheers.

Given the ongoing dispute I'll email

@bart great. editor@renewableheatinghub.co.uk.

@bart Hi Bart,

Well done for the improvements, there is room to make these system run cop 3.6-4.5 so there must be some more tweaks that can be done, its super important to match the ASHP to the flow rate and emitters output which starts with design (also works in reverse and essential to match the emitters to the output of the ASHP. 

1. The manufacturer's home help technical team have yet to respond to my request for 5kw turn down data- can anyone help?

Will need to know which manufacturer for the sheet, Mars no doubt will help you with this not to disclose at this point.

1. I've argued this would appear to show that my ASHP is too large, not that I need a bucket of warm water in my loft- Anyone have any resources that might confirm this please? The missing K3 in the kitchen would add volume but not much.

Please share the extensive heat loss and design report the installer and designer would have completed.

1. I've argued that a pump that can only achieve 14l/min given an ASHP that requires 17l/min optimal flow isn't compliant as it isn't fit for purpose. Anyone have any resources that might help please?

What is your pump model, where in the home (what floor) is it installed and how high is the highest radiator?

1. I've argued that flow/return thermostats that don't record flow/return temperature

   Posted by: @bart

   ↑

   Freeze stat function disabled as glycol had been added to the systems aren't compliant as they aren't fit for purpose. Anyone have any resources that might help please?

Are you talking about sensors here? if so not all manufacturers record in the log what they say but the system will be reading them to maintain that perfect 5º(DT)

@ashp-bobba Hi Bobba,

Thanks for your reply

I'm trying to find a way of sharing the latest heat loss survey (having removed all identifying info) and will share ASAP. My impression is that all ground floor rads are undersized as their 1st effort was an exercise in creative writing I've lost any faith in their data.

Pump is below:

For metering I've relied on outputs from the ASHP manufacturer's controller. (low =8, med =11 high =14l/min) Its on the 1st floor same height as highest radiator. x3 heating loops which combine before the main ASHP feed and return.

1. kitchen rad

2. x2 bd2 and bathroom rads

3. goes up through the loft to feed the BD1 & lounge rads (which is where they've put the volumiser I believe on the return). 

Thermostat/ sensors. Yes hence my concern. They appear to track rad F/R temps above 25/20 OK, (compromised by the 50litre lounge/bd1 loop)

Today DHW heating cycle (roughly delta 5)

 Thanks again

@bart Which county are you in? Kent by any chance? 

Send what you can and I will try to help.

KR

This:

being uninsulated ensures that any reading out of this will be completely off (unless you're interested in room temperature).

@mphb Which sensor is that supposed to be? I assume the primary flow or return?

All of the pipework should be insulated but yes especially that probe should be. 

That is something @bart would need to tell us. I have my probes firmly insulated and actually added thermal paste in order to get as close as possible to the temperature of the flow.

I cross my fingers that maybe it is this probe throwing the primary or return values off and so makes the ASHP work so inefficient.

@bart How you getting on with yours now? 

Just by way of a brief update.

Thank you so much for the responses received here and privately (given newbie status I'm unable to respond by mail). After hours spent suffering in silence it has been overwhelming to receive such generous support. Your time is very much appreciated.

Advice received to date has confirmed:

1. The system is oversized
2. The addition of a volumiser is madness
3. Things are compounded by the lack of a sufficient heat emitter in the kitchen and considering current performance a re evaluation of all rad sizing would seem appropriate
4. Given required Dt for heat transmission from rads min cc flow temps need to be increased (I'm guessing overlay a temp schedule? to keep internal temps as required).

Thank you for also highlighting the uninsulated pipework and the positioning of the probes as a concern. By extension the uninsulated pipework in both lofts could also improve efficiency.

Given my escalation I'm not allowed to make any changes myself, hence my 'call to arms' regarding information at this stage. That said your advice to date has been invaluable in tapering down the 'apparent' misinformation/avoidant responses I've received as a result of my escalations. Thank you RHH

Having taken legal advice I'm unable to share my heat loss survey at this time. I'm afraid I'll have to update once the relevant bodies have completed their investigations.

Thanks to the powers that be for creating such a forum