@benson It's good see that you're taking an active interest in the installation.
If your heat-pump is going to be satisfactory, then the installation must be based on good science.

That's very difficult for householders to achieve because it is almost certainly the first time you've commissioned such work to be done.

As for the mounting options...

There are quite a number of wall-mounting kits available.
They will support different weights of unit, at differing distances from the wall, and may offer particular features.
Here's a unit offered by BES:

Some wall-mount kits have an optional condensate tray which allows the water to exit into a pipe.
That means it can be guided to a suitable drain point, rather than form an ice rink with stalagmites beneath the ASHP in winter.

On the negative side, a wall mount system requires effective anchor-points in the wall.

It's not just a case of choosing the right type of bolt.
The wall structure itself needs to be taken into account.

I would feel comfortable using expansive bolt anchors in a concrete block wall in my area of the West Country.
But I'd be less inclined to install that type of fixing for a wall in Wiltshire.
The type of sand used in the mortar is different, and that's where local knowledge and experience matters.

A 'chemical bolt' might be a better choice. It uses an epoxy resin pocket to hold the bolt into the wall.
That avoids stress lines being formed when an expansive bolt fixing is tightened.

An experienced installer will have a range of tools, techniques and materials in their arsenal.
Their choices should be governed by the underlying science...

... not just opinions and personal preferences.

Thanks all for the input. Sounds like the base is getting sorted this weekend. Was promised confirmation today though and unsurprisingly not heard a sausage from them. That said they know my expectations at least and they intend on installing the unit (which has now arrived) next week.

Now just need to drain the system down tomorrow and rectify some wonky towel rail pipework they have installed. Even their second attempt (after I told them to redo it) isn't anywhere near straight, so just easier to do it myself. Furthermore they told me the CH and HW would remain functional until the last day yet left the system well below 0.5 bar with no attempt to bleed any air out of it. Considering the delay when it was supposed to be finished last week, a bit more care and consideration would have been appreciated...

Here on the Forum we see the same sorts of mistakes occurring regularly.

A pipe that hasn't had a spirit level near it isn't likely to affect the overall efficiency of the system.

However, the things I'd be looking out for are:

• pipes of too small a diameter to transfer enough heat
• pipes with elbow bends, where a swept bend would've offered less resistance to the flow
• poor pipe insulation, especially around the valves, sensors, pumps etc.
• pipe entry points through the outer wall being left uninsulated and/or unprotected by an outer sleeve
• incorrect insulation on external pipe-runs; must be UV resistant

If you think you might be seeing any issues like these, please post photos.

@transparent thank you. The pipework itself is ok. I ended up insulating it albeit am going to remove it and redo it just because they are quite long tails (if that is the right term) up to the valves and it is going to annoy me once the bathroom is finished and all I can see are the pipes going off at different angles. Unfortunately one is off at an angle one way, and the other in the opposite direction is it is really noticeable, or to me at least. I'll be getting my trusty pipe bender out to minimise right angles etc. I'm not an experienced DIY plumber by any means but I am confident I can do a better job than they have managed. Their first attempt was quite frankly a joke.

I will certainly be keeping an eye on the external pipework and insulation. That is one aspect that I have to say is looking very neat in terms of what they have done but I believe their first fix pipework will now be too short for an on the ground install as they were anticipating it would be a foot higher.

Posted by: @benson

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I will certainly be keeping an eye on the external pipework and insulation.

For external pipework, it is crucial that it is weather-tight.

If rain can get between the pipe and its insulation, then it draws heat out and throws it away on the ground.

See what I've previously posted about this here in a topic about a 'bad installation' with graphics.
That's a pretty long topic, and there's loads of other useful information there which is worthwhile reading.

Thanks I will have a read of that and keep an eye on the weather tightness as well.

I've redone the slightly wonky pipework to one of the rads as well today so that is all sorted, and refilled the system properly so at least we've got an operational heating system until they come back. There were two or three 90/45 degree press fit connectors on one side which was a bit odd as all it needed was a bit of pipe bending in one section to get it aligned correctly. Anyway now all sorted with one straight solder ring connector on each side rather than multiple press fits. All good fun on my day off 🙃 

@transparent Just reflecting again on the rubber feet in your earlier post and the mountings on this bracket. They are so different in terms of anti-vibration properties.

I have the bigger version of this BES (CBR) bracket above, and the mountings on them have almost zero anti-vibration properties. It wont be an issue for a small pump I shouldn't think but it is a risk for larger ones, including to compliance with building regs part L and planning/MCS (MIS3005-I).

The mountings provided in the CBR bracket from bracket to wall are hard plastic - zero AV properties and channel vibration to brick through 2 tony 1cm square nubs. Mountings provided for the unit to sit on on the bracket arms are stated in the spec as "anti-vibration" but they aren't, They are 5mm thick and hard rubber - useless.

If anyone goes anywhere near a CBR bracket, they should seriously consider spending the £30 (or instruct your installer to) on 4 x properly rated AV grommets of 35mm or thereabouts for it to sit on to guarantee they and their neighbours if attached never have issues with dreaded vibration noise emanating into bedrooms etc. I'd say always always always ground mount where possible, as CIEH advise.

@elton some useful info- thanks. More evidence that any form of wall mounting in a domestic setting will only benefit the installer, in general terms. Plus, why would I want big holes drilled into my brickwork if I can avoid it. Not to mention the aesthetics and industrial appearance of wall mounted units.

They are coming this weekend to sort the base- I suspect with some associated grumbling about my unreasonableness again but the CIEH info that you have provided will come in handy when we debrief this intervention with them.

Hi again all,

The good news is that the ASHP is now in, and installed on a concrete base.

Anyway, the slight niggles continue (and me continuing to tell them to redo various things). It's not quite fully installed yet, main thing being the homely controller they installed doesn't work so I have no way of controlling heating as yet besides the clivet controls in the airing cupboard- which is basically on or off and I have to be in the house to do it. The homely definitely looks old/used to me, and no box or instructions so I've told them that I expect a new one with proof that it is new.

A few other queries I had:

- Is bricking/blocking old flue up reasonably standard when it comes to ashp installations or does it vary?

- What paperwork should I be provided? They say they are MCS registered and it would be guaranteed by them, albeit can't find them on their list of installers.

Thanks

@benson With regard to the Homely controller; when mine arrived, it was properly boxed up with Homely unit instructions and separate D.Comm installation/setup instructions (very detailed), internal partitioning in the outer box housing the Homely controller, the D.Comm unit, the two PSU’s with neatly coiled-up power leads. There was a pack too containing a resistor for termination purposes, several tiny plastic fittings and some self adhesive pads and cable ties - all neatly packed. If yours arrived without such, I think you have reason to be saucepicious! Regards, Toodles.

@toodles thanks. What I have is an old and dirty looking hub, and the node which looks like an old version as well. The version numbers don’t match either. It is 100% old stock.

Ive challenged it, and they’ve ordered a new one apparently without too much fuss. I know they removed a homely from one of their customers who we went to visit (who highly recommended them), so I suspect I have his old one. That previous customer couldn’t get on with app controls.

It has also transpired that they definitely aren’t currently mcs accredited, as I contacted them and ofgem today, so I believe they are going to use my install to accredit themselves? Disingenuous at best as they clearly advertise that they are mcs accredited and that our install would be insured through them.  I suspect things are going to get interesting when they want to settle up and they have to wait for this accredition and guarantee paperwork before I pay the final invoice. There is no application for a bus grant against our property either.

Oh dear!

How close is their behaviour to fraud? Over the line in my personal judgement. I’d be down to Citizens Advice for chapter and verse if it were me. I hope you have a huge residual payment that you can withhold.