Mitsubishi Ecodan ASHP - Crippling Bills due to electricity usage.

Gerry1

shinytop said:

Gerry1 said:

Could there be a less intuitive control panel than that Mitsubishi one?

Does it come with a residential course that explains how to use it?

No wonder people can't get the best from their heat pumps and end up with crippling bills...

To be fair it's not too bad considering it almost avoids using any words at all and relies mostly on symbols.  There are some quite good YouTube videos on how to use it 

That's precisely what the problem is !

You have to guess what the symbols mean, whereas words would be quickly and easily understood; a well designed interface wouldn't need a YouTube video.  Using symbols rather than words is just a penny pinching exercise so that the same unhelpful device can be sold internationally.  Sadly, everyone ends up equally confused and doesn't get the best out of their system.

Same with cars, no wonder you see many people driving in clear conditions with fog lights on.  If FOG were displayed on the dashboard they'd realise immediately, but the meaning of the symbol is often not understood.  The worst example is the aircraft emergency instructions sheet, devoid of all words except BRACE BRACE.  If asked to explain the meaning of the pictograms I suspect the average score would be dangerously low even if people took the trouble to study them which most don't.

The answer is to use words as well as sensible pictograms, then people would have a better chance of getting the best out of their expensive heatpumps.

LozT

Hi all

Many thanks for coming back with comments. Sorry it has taken so long to reply. 

We did end up getting a professional to come out and take a look at the system. 

He confirmed that the old owner should have been advised that the radiators in the house are not suitable for use with an ASHP. The majority of them are all single radiators with no convectors, so for them to work effectively they need a water feed temperature of at least 80, where the pump is only set to have a maximum temperature of 50. He said in most rooms, with the poorly insulated walls and old double glazing (over 10 years old) the heat being lost is about equal to the amount of heat being added by the radiators so the rooms are never going to fully heat, so the thermostat (we only have one downstairs) will not reach the desired temperature and the pump will continuously work at its hardest setting to try and heat the house. It does not look like the thermostat was upgraded either when the system was put in, so it just has a temperature setting on it not a timer setting, we have tried to set the temperature setting to be the same on both the Ecodan controller and thermostat.

 

The professional said we really need to have a survey done to accurately work out what the heat loss of each room is and upgrade the radiators accordingly (whilst also thinking about insulating the walls if practical). Long term he said if we are doing rooms up we should think about putting in underfloor heating & set up zoning so we can separate upstairs from down.  

 

He did adjust some of the settings – it looks like the hot water immersion heater was set to come on after 10 minutes if the hot water hadn’t heated enough with the pump so he’s changed that to give the pump a chance to heat the water. He was also able to see how much electricity the pump was using and did say it was very high but not surprising with the above mentioned issues.

 

In terms of RHI it looks like the intent was there for the old owner to be able to claim, as the boiler is connected into the system but the boiler return pipe has been cut to stop it being used. However reading the comments our EPC rating was not that good, so it wouldn’t surprise me if the old owner applied but was rejected. He did say we could reconnect the boiler and have it working as a bivalent system so the gas system would take over during very cold weather. Not what the government wanted but if it’s cheaper then so be it.

 

Anyways for now until they can come back and do the survey and get the correct radiators installed, we have opted to switch the heating to only come on for a couple of hours in the morning and use our woodburner to keep one room warm downstairs.  

Laura

Reed_Richards

You need to ask your Professional if he can convert your system into one which can claim RHI.  This might be possible if he performed the appropriate heat loss calculation and installed the right radiators (and if he is MCS accredited).  Your EPC rating does not have to be at all good but it must not recommend extra loft insulation or cavity wall insulation.  If you go down this road you only have weeks to get it all done.

You can still claim RHI on a "bivalent" system but the process is more complicated as you need extra equipment to measure the amount of heat provided by the heat pump.

LozT

@Reed_Richards - Many thanks for coming back.

I have since spoken to the company who installed the unit (I managed to get their information from the MCS database)

They have said we wont be able to apply for the RHI payments as it is supposed to be the owner who commissioned the installation of the system who needs to apply (not sure if this is true or if they are bogged down with other RHI requests and they don't want to help with another one before the 31st March deadline). If this is true we are stuck. It also looks like they didn't issue the certificate immediately so it wasn't issued until after he'd passed away, which is probably the reason he hadn't begun the RHI application. I did ask them if they would have done the heat loss calculation and to make recommendations on the radiators. They said they would have done the calculations & would have recommended he change the radiators, but they couldn't force him to change them. 

I have also taken a look at our EPC details. The very first recommendation on it is cavity wall insulation. The second recommendation is floor insulation, so I assume we are a no go on getting the RHI payments based on this alone as we really wont have chance to get this done in the next 6 weeks. :-( 

Reed_Richards

Based on your account of the company who installed the heat pump I am not inclined to trust them

You have to have an EPC that is less than 2 years old to claim the RHI.  And you cannot claim RHI if your EPC recommends adding cavity wall or loft insulation.  So the previous owner could not have made a successful claim for RHI.

I don't know this for sure but I would have thought that MCS accredited installers must install a heat pump that is fit for purpose so if the client refuses to change the radiators then I don't think the installation should go ahead.

At present a gas boiler is cheaper to run than a heat pump that is installed properly.  In your situation I think your best option is to go back to gas.   



  

shinytop

Reed_Richards said:

Based on your account of the company who installed the heat pump I am not inclined to trust them

You have to have an EPC that is less than 2 years old to claim the RHI.  And you cannot claim RHI if your EPC recommends adding cavity wall or loft insulation.  So the previous owner could not have made a successful claim for RHI.

I don't know this for sure but I would have thought that MCS accredited installers must install a heat pump that is fit for purpose so if the client refuses to change the radiators then I don't think the installation should go ahead.

At present a gas boiler is cheaper to run than a heat pump that is installed properly.  In your situation I think your best option is to go back to gas.   



  

@LozT

sorry for all the issues you are having.  Why don't you phone the Ofgem RHI helpline?  I have a couple of times; they actually do answer and they are quite helpful.  The number is 0300 003 0744.  

I can't pre-empt what they'll say but I would have though the original owner dying would be a valid excuse for you registering the installation. I suspect your installer is just bu115***ting.

The EPC might be more difficult but I have heard of there being exemptions allowed, for example if it's physically difficult or may cause damage to the building. BTW you don't need to get floor insulation; cavity wall and loft are the only compulsory ones. 

As far as I know the ASHP must be capable of delivering the heat energy (that's the 20,000 kWh or so number) on the EPC.  I don't know how far they assess the radiator specs or room temps, although they are part of the MCS calculation spreadsheet.  My radiator specs in my MCS spreadsheet are only vaguely similar to what I ended up with.

As @Reed_Richards says, gas will be cheaper.  But a successful RHI claim will probably make up the difference and allow for some new radiators. 

If you do get rid of the ASHP, don't forget one like yours costs about £6k so will be worth something 2nd hand.

LozT

@Reed_Richards - It wouldn't surprise me if the installers took the old owner for a bit of a ride. They also installed the pump on a flat roof right above the front door, which visually looks terrible and noise wise vibrates a lot into the house as it isnt on anti vibration feet. First thing we asked the company that came around to take a look was can it be moved. 

@shinytop - Thank you for the number. I shall give them a ring. I do think the cavity wall might be a sticking point though as I cant see any reason why the property couldn't have it as I don't think it would damage the building and there are no difficulties with access. 

I think we will go down the bivalent route especially if the government do go ahead and stop new boilers being sold in 2030. We'd only end up having to put a new pump in in 20 years time so might as well try and deal with the insulation issues now. At least that way we can use the gas as a more economical route for now then do our bit for the environment thereafter.  

I would also add that I do find it amazing that the EPC rating dropped once the ASHP was installed. I can see the EPC certificate from when the last owner bought (he only owned it for 5 years). That one said the main heating and hot water were both rated good (mains gas boiler & radiators). They both dropped to Poor with the ASHP.

Reed_Richards

@LozT - the only way to make your heat pump viable is to replace your radiators with ones having a much large surface area.  If they are old panel radiators this is quite easy because the ones with internal fins may well be sufficient without needing something that takes up a much larger area of wall.  Do as the Professional you engaged recommended and get a proper heat loss survey made.

Reed_Richards

LozT said:

I would also add that I do find it amazing that the EPC rating dropped once the ASHP was installed. I can see the EPC certificate from when the last owner bought (he only owned it for 5 years). That one said the main heating and hot water were both rated good (mains gas boiler & radiators). They both dropped to Poor with the ASHP.

Amazing but always true, not just in your case.  EPCs see all forms of electric heating as equally bad.  This will have to be put right one day but nothing is happening about it now.  

happy_dude_3

Hi Laura,

Did the people who came round and checked your ASHP check the main heating feed / return pipe to the ASHP? 

We moved into a large house with an 8 year old ASHP about 18 months ago, and found that the heating demand was crazy. We've done quite a few things to improve it, but one of the main ones was to properly insulate those pipes. It had a long run from the ASHP to the distribution manifold (~10-15m), through the attic, which was above the loft insulation. This meant that a lot of the heat meant for the house was just getting lost before it got into the house. 

We got the wraparound climaflex pipe insulation and made sure they covered everything and joined together with aluminium tape, and then buried the pipes under 2-300mm of normal loft insulation. Also the short run outdoors we improved the thickness of the insulation, and made sure it was suitable for outdoors. We immediately felt the improvement with warmer radiators and a more stable room temperature. 

Hope you can sort out your issues with the ASHP.