@crimson That 50 litres of water in the buffer tank, has this been plumbed as the LLH was? Were it plumbed as a two port volumiser, then the loss of space in your airing cupboard / utility area or whatever might be a sacrifice worth making as it would certainly provide the extra volume of water your system may have lacked. Well insulated, it might be a worthwhile move. Regards, Toodles.

Hi @toodles , hope you're keeping well!

It's been plumbed in as a 4 port LLH/volumiser combination.  Much to my annoyance when the specialist wanted it to be a 2 port volumiser just on the return to aid with system volume.

However installers stuck with Grant's requirement with their install pack to have a LLH.  The installer today said he always uses the 5L/other small ones and never had issues.  What's frustrating here is had they actually came and spent time investigating (like I kept asking them to and the builder to) - they may have spotted the pump in the Grant being faulty (and sooner!).

What I'm concerned with now is, a) pump replace - great if that works, but b) now have 50L LLH which could itself cause mixing etc.

Here it is:

(Ignore lack of lagging for now, they're coming back tomorrow/Friday to sort that)

@crimson ☹️ I feel it is time the manufacturers came to their senses and listened to sense concerning LLH v Buffer v Volumiser. In the Q&A presentation that @editor put together, the only indication of any LLH or Buffer Tank benefit did not make it to the presentation as not one invitee would speak up in their favour yet manufacturers still appear to be exercising rear-end protection measures by insisting on their use. Regrets, Toodles.

Posted by: @crimson

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@jamespa be very interested to know your thoughts on this.

A 6L LLH replaced with a 50L one…could that cause more issues?

I'll hopefully have the pump on the Grant ASHP replaced tomorrow, he mentioned they should have just hit a 2:30pm cut off that Grant stated for it to be sent out at 3pm and arrive to installers tomorrow.

Turns out I do have a defrost valve by the Grant ASHP too.………(think different people attending from the installers hasn't helped matters).

I think it's unlikely it will make things worse.

The pump issue is yet another example where a buffer not only degrades performance but also obscures faults.  Without the buffer and auxiliary pump there would have been no flow at all which is easily detected

Posted by: @jamespa

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Posted by: @crimson

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@jamespa be very interested to know your thoughts on this.

A 6L LLH replaced with a 50L one…could that cause more issues?

I'll hopefully have the pump on the Grant ASHP replaced tomorrow, he mentioned they should have just hit a 2:30pm cut off that Grant stated for it to be sent out at 3pm and arrive to installers tomorrow.

Turns out I do have a defrost valve by the Grant ASHP too.………(think different people attending from the installers hasn't helped matters).

I think it's unlikely it will make things worse.

 

That's good to hear.

I truly hope this 10 minute replace of the pump will do the job and I can sign off this project and move on!

Posted by: @crimson

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I'm off in December, and may invest in some kind of heat gun where it's quick and easy to see deltas across rads, and balance the rads again

Definitely worth getting numbers.  It's generally differences that matter so a cheap amazon probe is fine as long as you use tge same one consistently strapped and preferably covered with insulation.  You need to measure when something is happening, ie it's heating, preferably when the problem is evident as well as when it isn't.

Posted by: @jamespa

↑

Posted by: @crimson

↑

@jamespa be very interested to know your thoughts on this.

A 6L LLH replaced with a 50L one…could that cause more issues?

I'll hopefully have the pump on the Grant ASHP replaced tomorrow, he mentioned they should have just hit a 2:30pm cut off that Grant stated for it to be sent out at 3pm and arrive to installers tomorrow.

Turns out I do have a defrost valve by the Grant ASHP too.………(think different people attending from the installers hasn't helped matters).

I think it's unlikely it will make things worse.

The pump issue is yet another example where a buffer not only degrades performance but also obscures faults.  Without the buffer and auxiliary pump there would have been no flow at all which is easily detected

 

Oh completely, he even said without the hydraulic break either a secondary pump would have taken over or it just would have obviously not been running.  Just madness.

The manual flow setter being blacked out with gunk I guess also hasn't helped (he said he doesn't like manual ones - so why have one in?!!??).