@goody is that all your rooms? It doesn't mention any bathrooms or toilets. It also looks like the MCS calculator so it's a shame they didn't give that to you as it has a radiator sizing tool in that they probably filled out

1: Pipe going through a wall must be contained within an outer sleeve. There must be no possible contact between the material of the wall and the pipe itself. The sleeve must slope towards the outside at an inclination not less than 1 in 40.

2: Yes, the pipework should be insulated for the entire run, including the section where it passes through the wall sleeve.

Assuming you have 22mm dia pipe and insulation with a 25mm wall-thickness, that means the internal dimension of the sleeve must be greater than 72mm per pipe.

If the in-wall pipework insulation is to drop to a 19mm wall thickness, then the inner diameter of the sleeve becomes 60mm. But the entry points on the exterior face must then also have some sort of insulated collar.

If it was me doing this work, I'd cut a circular piece of EPDM rubber about 200mm diameter, with the pipe-hole cut through the centre, and glue it to the face of the wall. That provides a rain-resistant 'gasket' and prevents insects nibbling their way along the pipe insulation into the house!

The pipe entry points into the building are a substantial part of the installation work. They can't just use an SDS hammer-drill and drive a couple of 24mm holes through the concrete blocks! 😖 

Posted by: @transparent

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1: Pipe going through a wall must be contained within an outer sleeve. There must be no possible contact between the material of the wall and the pipe itself. The sleeve must slope towards the outside at an inclination not less than 1 in 40.

Cool. Who says it must? The rubbish way the pipe passes through the wall is one of my outstanding complaints with my installer too! I bodged some installation onto it in the worst of last winter, thinking the installer would soon return to finish it, but nope, so I've got to get someone else to finish it AND complain/claim to the guarantee body. If those "must"s indicate that a law or required standard hasn't been followed, it would help me immensely!

Posted by: @mjr

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600kWh so far this month is not outrageously high for an upgraded 1930s home

Just for some perspective, I have been approaching that figure per week during the cold spell. Total Dec use to date (this morning) has been 1281kWh and I have had downstairs not reaching design temps. But I do have an old leaky building which I am slowly sealing up bit by bit. Over the cold spell, I found yet another leak - through the microwave ventilation grills! Cold weather is the best time to detect leaks, because you can literally feel the cold air. The microwave is built in and is partly recessed into the non-cavity wall, nonetheless the cavity is itself a draught magnet, which then escapes from the ventilation grill under the microwave. Not sure how I am going to plug that one without setting the microwave on fire...   
 

Sheesh @mjr that's more complicated to prove than you might at first imagine.
I was rather hoping that common sense would be sufficient to allow my comments to stand!

The rules depend on whether the feature being passed through the load-bearing walls of a dwelling are an electricity cable or a pipe carrying water or gas.

 

The IET Wiring Regulations for electricity contain clauses such as:

522.8.2 Where buried in the structure, a conduit system or cable ducting system, other than a pre-wired conduit assembly specifically designed for the installation, shall be completely erected between access points before any cable is drawn in.

and

522.8.14 No wiring system shall penetrate an element of building construction which is intended to be load bearing unless the integrity of the load-bearing element can be assured after such penetration.

 

Turning to pipes:

Pipes being passed through a wall need to be protected from both mechanical stresses/abrasion and the possible effect of chemical reaction to substances in the mortar/concrete. The latter issue most commonly affects copper pipes.

Moreover, the pipe channel must comply with the requirement to prevent the passage of vermin, in just the same manner as applies to whole building envelope.

 

Gas Regulations 1998:

19.—(1) No person shall install any part of any installation pipework in a wall or a floor or standing of solid construction unless it is so constructed and installed as to be protected against failure caused by the movement of the wall, the floor or the standing as the case may be.

BS 6891  Installation of low pressure gas pipework of up to 35 mm in domestic premises:
8.10.2 Sleeves shall pass through the full width of the wall or the full thickness of the floor. Sleeves shall not impair the fire resistance of a building.

 

Building Regs, 2021 Approved Document Part-L; Continuity of Insulation

4.15h. Penetrating elements include steel beams, incoming services, meter boxes and sub-floor vents.
Designs should clearly indicate means to limit disruption to the insulation. For recessed meter
boxes on the cold side of the construction, insulation should be installed behind the enclosure.
For incoming services, insulation should fit tightly around ducts, pipes, etc.

4.24 In a new system, all of the following new pipework should be insulated.
a. Primary circulation pipes for heating circuits where they pass outside the heated living space,
including where pipework passes into voids.

Appendix B7 Photographs should be taken of typical details as listed below and should be unique to each
property. One photograph per detail should be recorded.
6. Building services: for all plant associated with space heating, hot water, ventilation and low or
zero carbon technology equipment within or on the building, show the following.
a. Plant/equipment identification label(s), including make/model and serial number.
b. Primary pipework continuity of insulation.

 

WRAS Water Regulations Part-G

G 7.2 Pipes entering buildings at the approved depth should be passed through a duct and the ends of the duct sealed.

For the purposes of this document a ‘duct’ or ‘chase’ is defined as:
Duct/chase: covered channel which may where appropriate contain insulation but no other materials such as backfill, plaster, screed or cement.
Wrapping in insulation alone is not recognized as an acceptable method of ducting.
Advice on acceptable methods of ducting is provided in clause 4.7.3.2 of BS EN 806 – 4: 2010.

 

Is that enough to be going on with @mjr ?

Posted by: @oswiu

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@goody is that all your rooms? It doesn't mention any bathrooms or toilets. It also looks like the MCS calculator so it's a shame they didn't give that to you as it has a radiator sizing tool in that they probably filled out

No we have an ensuite, bathroom, downstairs toilet and basement toilet and upstairs landing which even though they are relativley small rooms, I suppose they all add up to quite an omission.

Mitsubishi sent me this earlier:

"Thank you for getting in touch.

As you point out the initial survey is very important. If this has not been completed properly then this could lead to an undersized Heat Pump and cold property as you’re experiencing. Unfortunately, as a manufacture we have to trust companies to install and apply our equipment correctly, we can train, help and advise them but ultimately is their responsibility.

 Your options in term of heating to answer your question as I see it are below.

• Engaged a new installer, one who you trust to evaluate your property and current system. Listen to their suggestions
• Revert to a gas boiler

 

If the heat pump is correctly sized and installed, including upsizing of pipework and radiators and improved insulation where needed. Internal comfort levels will be comparable to a gas boiler."

 

Posted by: @cathoderay

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Posted by: @mjr

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600kWh so far this month is not outrageously high for an upgraded 1930s home

Just for some perspective, I have been approaching that figure per week during the cold spell. Total Dec use to date (this morning) has been 1281kWh and I have had downstairs not reaching design temps. But I do have an old leaky building which I am slowly sealing up bit by bit. Over the cold spell, I found yet another leak - through the microwave ventilation grills! Cold weather is the best time to detect leaks, because you can literally feel the cold air. The microwave is built in and is partly recessed into the non-cavity wall, nonetheless the cavity is itself a draught magnet, which then escapes from the ventilation grill under the microwave. Not sure how I am going to plug that one without setting the microwave on fire...   
 

Well that has made me feel slightly better! i found a draught coming in through a tiny hole where i had hidden some cabling years ago behind a tv ! You correct about cavities being draught magnet! I honerslty thought out house was draught free until this last week! Out of curiosity what type of house do you live in?

 

Thanks!

 

Posted by: @skd

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Posted by: @goody

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Posted by: @skd

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Are you using MelCloud?  If so, you can select the flow and return temperature curves (in Reports, select Hourly Temperatures) and you can see if your actual flow temperatures are achieving the desired set point.

I was never shown how to use MelCloud as the installer said it work differently, due to us keeping our exisiting radiator heating controls- 7 x Drayton Wiser radiator valves and underfloor heating controls- 5  x wired roomstats

 

That's a disgraceful approach from the installer IMHO.  MelCloud gives the user access to useful data about consumption values, graphical trends, system and outdoor temperatures etc, just to mention a few.  Not using it for control is no excuse to steer the owner away from it.

Do you have the wifi interface, that enables remote access?  If you do then you can still download and set up the MelCloud app if you want to.  There are some helpful tutorials on youtube.

 

When i open up melcloud, there is minimal information maybe due to the separate controllers. I can not find anything to do with what you mention: consumption values, graphical trends, system and outdoor temperatures

 

@goody missing out five rooms is a big oversight. This system will never be enough to heat your house when it's cold no matter how many minor improvements are made. I'm afraid Mitsubishi are right, you need to contact another installer to get this fixed. Perhaps a hybrid system would be the least disruptive and expensive.

Posted by: @mjr

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Posted by: @goody

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I was never shown how to use MelCloud as the installer said it work differently, due to us keeping our exisiting radiator heating controls- 7 x Drayton Wiser radiator valves and underfloor heating controls- 5  x wired roomstats

That, plus the words "controller installed in loft" on the schematic worry me. Are the Mitsubishi controls in the loft, or is the FTC panel somewhere else? If that's in the loft, I think you won't even be able to try the much-vaunted auto-adaptation mode (which has only just started working for me again in certain conditions, but others report success with it) without buying a Mitsubishi room temperature sensor (or control containing one). Corner-cutting muppets of installers! But weather-compensation should still be possible, even then, and the FTC seems pretty good at it.

As I understand it, the best approach with "foreign" controls like radiator valves is to use them only as protection against overheating a room, with the weather-compensation curve set to achieve and maintain the desired room temperature with the system balancing itself. The foreign controls shouldn't dictate the heat pump operation because they don't understand the Ecodan as well as its own controller. How much a Low Loss Header hinders the system balancing itself, I don't know.

 

The controller is in the airing cupboard in the bathroom. It was inaccessible, until i relocated to just inside the airing cupboard door after Hero Renewables left.

Only a couple of days ago I had to completely replace the whole condensate pipework run after i discovered it was only 22m of un-insulated pipe, which is why i had multiple icicles coming from the bottom of the heat pump where it was overfloweing onto the side path. I replaced it with 40 mm pipe and it's now draining away, safely

I have put it into weather compensation mode.

Its weird how when things go wrong you realise you may have been a bit gullable letting cowboys in and believing everything they say because they were had 'Trustmark Government Endorsed Quality' and were 'MCS Certified'. What a load of tripe! You live and learn!

Thanks

 

@oswiu 

 

Posted by: @oswiu

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@goody missing out five rooms is a big oversight. This system will never be enough to heat your house when it's cold no matter how many minor improvements are made. I'm afraid Mitsubishi are right, you need to contact another installer to get this fixed. Perhaps a hybrid system would be the least disruptive and expensive.

 

Hybrid? ...like a gas boiler backup or something else?

What options are there?

@goody yeah I think they normally work by using a heat pump for most of the year then turning the boiler on instead below a certain ambient temperature. I don't know much about them to he honest so they may or may not be easy to retrofit.