Welcome to forums @ericdo. I've created a new thread for you, so please share your experience with us. I'm very sorry to hear you had a cowboy installer. Sadly, this has been the case more and more frequent with recent installations. Would like to hear what went wrong and if you have any plans to remedy the issues.

If you process your paperwork in the coming days, you'll make the RHI deadline comfortably.

Hey Cool. Thanks Mars!

So, on the many bits of Admin I need to get through, the most pressing is the RHI application. I'm hoping to get it in before the end of Dec as I think it will get rebalances going into 2022 before the rush. Obviously I want to get the correct figures in so as to maximise the RHI payments

A few questions for you knowledgeable folk

1. My MCS Certificate lists space heating at 15708 (Space Heating) and 3286 (Water Heating). My supplier says these figures came from the original Heat Loss Survey undertaken when they quoted. That was before the extension completed. The latest EPC was commissioned after the installations and extension completed. Those figures are 24558 and 2970 respectively. Which figures will the RHI calcs use, and should I insist on the MCS certificate being rectified?

2. The supplier set my flow temp at 40 on the MCS Certificate. I've been running it at 32 for the last few months. Is this figure a factor in the RHI calcs? Or do they only use the SCOP? Again, should I insist on the MCS certificate being corrected?

3. My EPC says that I need room in a roof insulation. The EPC guy says that was the way he had to fill out the forms, as he could not see the insulation. It got fully redone during the build, so up to building regs standard. Is the system going to reject me?

All seems so daunting, and it's important I get it right consider the ~£11k I outlayed.

Thanks. Eric

@ericdo 

The RHI application uses the latest EPC, not the MCI numbers.  It's capped at 20,000 kWh per year.  My MCS number was a lot less than my RHI one. It's actually better for you the worse your EPC number is. The MCS number should be more accurate because it's a proper heat loss survey.

I think the SCOP used is the one from your ASHP in the link below, at your design flow temp.  That certainly fits with my RHI numbers.

https://mcscertified.com/product-directory/

You only need to do what the EPC says if it tells you to get normal loft, or cavity wall insulation. 

I got about £11.2k at the maximum 20,000kWh. It's very easy and quick, as long as the installer has registered you properly. 

Kev

@kev-m

Thanks for the response. That link makes sense. I guess I could take a punt and submit at those figures. I'd like to submit before the end of the month. Can you remember if you got a calculated amount before you hit the submit button, or after you had done the submission?

On a related but slightly off topic point, I had a small win yesterday. I've spend loads of time trying to correlate energy usage to the time the thermostats turned on. My builder installed a Heatmiser wireless system. I noticed that the ASHP would turn on for about 15 mins each hour, even when none of the thermostats were calling for heat. Also I started to realise that even when one of the thermostats was calling for heat, the wiring centre was not activating the actuators.

After rereading the manuals and call to Heatmiser, I discovered that three of my Thermostats were not connecting to the wring centre properly.. A quick reset later, and about three hours to warm up, I have an evenly warm house, and an ASHP that did not turn on once all night 🙂 Here's hoping that the energy usage becomes a little more stable. The wiring centre was calling for heat for 12 mins every hour when it could not communicate with the thermostat....

Lesson learned is to triple check everything the installers do. I had assumed that because some heat was coming through that the thermostats were configured correctly.

@ericdo 

that's good news about the system.  

For the RHI figures, you don't submit them, the installer does.  My application uses a SPF of 3.77. This is from the link above for my ASHP at the mean radiator temperature my MCS calculations used, which in my case was 46C.  This is from my RHI application

and this is the Ofgem doc that describes how the calcs are done (page 42).

file:///home/chronos/u-9e9fa1964cdc2b06db47573578a582b667d04746/MyFiles/Downloads/drhi_referencedocument_mar2021_v7_0%20(1).pdf

Just try the application and see what happens.  You'll need the reference number from the installer. I only got the number once I submitted but it was similar to what I worked out. I got a bit more than I thought because I assumed the SPF was lower. The higher it is, the more you get.

@kev-m Thank You!!!

I did it all and it was approved right away. Quite rewarding to see "red tape" systems like this all work. Clearly their systems are linking back to the EPC and to the MCS Cert. I was worried that this would be a struggle as my EPC recommends roof in room insulation. Like magic however, it all went through

Thanks for helping me with the calcs. Retrofitting your numbers and mine, I was able to calculate in advance what I should get, and it was only out by a few pounds. Interestingly I got about £65 more than the overall invoice from the installer. Feels like these quotes are beefed up to match the exact expected amount.

Also the installers error on the flow temp cost me about £200 over the 7 years, but I can't complain too much if the total payment exceeded my bill (less interest of course)

Thanks again.. So glad my costs for this thing are now covered

Now onto my next 3 complaints from the neighbour...

@ericdo 

thanks for updating.  It's also a nice feeling when the first payment goes in 😀 

My RHI will cover about 70% of the overall cost but then I started with absolutely nothing and I'll be saving lots compared weith the storage heaters.