John Mckay

Morning ProDave, Thank you. Yes, I have an air-source heat pump (I forgot to add that detail into initial post !), which is why I am struggling to understand why the housing association would marry the two, there is no storage heaters to speak of! I have attached a picture below of my two fuse boxes. I keep wondering, 'should the heat pump be part of the standard rate box?' ''SSE THCT tariff is not a good rate'' From what I can see, if I do need to change it, I will be asking the housing association to pay for the switch. There is an excellent report (https://www.changeworks.org.uk/sites/default/files/ImprovingConsumerOutcomesFund_Report_April2020.pdf) from 2020 that explains the problems of THTC in the North-West; interesting read, if the TV is on the blink!

Anyway, I know this is know a massive post!

-----------------------Ecodan System, NW Scotland, some questions. Hello, first off; many thanks to the forum! Two weeks ago, I came across the forum and began furiously adjusting the settings on my FTC-5 controller. I have further questions though, perhaps not urgent, but have been bugging me since moving into the flat earlier this year. Description of space: 1st floor flat, 2 bedroom, myself, and my son only. I work from home (a relatively recent development) so at home most of the day. The meter is on THTC (total heating, total control), I am next to completely ignorant of the tariff and how it affects my bill – this has changed in the last couple of weeks since focusing on the flat - the heating, the drafts! the flooring, the lighting, etc. I use the shower once a day, my son has three baths a week. The shower is electric. THTC: From SSE, ‘If your home is all-electric and you live in the north of Scotland, you could be on Total Heating with Total Control (THTC). It works best with electric storage heaters rather than gas, oil, or wet electric heating. With THTC you get two meters. One is for off-peak energy you use and the other records all your normal usage like lights, kitchen appliances and sockets. Just so you know, energy used on the normal meter costs more than our standard rate. What are the times for THTC? The specific time for the off-peak rate depends on the weather forecast for your area, but you'll get between 5 and 12 hours each day. THTC works by storing up heat in your storage heaters and hot water tank during the off-peak times. Other electric heaters and heated appliances can also be used on the cheaper rate. The off-peak rate is available 24 hours a day for panel heaters, focal point fires, bathroom heaters, towel rails, the hot water boost, and even electric showers. You'll need to get an electrician to make sure all those appliances are connected to your cheaper-rate meter if you're not sure.’ Okay, thank you for reading so far! Now, my questions. 1. Should I keep my system at a higher temperature? Now I am controlling it with the ‘flow temperature’ at 33/36’. The temperature in the flat is … mild, which I personally am fine with as I ‘run hot’. But I keep reading the system is best used ‘at max’/at 45’ – should I increase this? 2. How does the billing work?! From the above my understanding is the Ecodan is running on a lower rate for 5-12 hours a day, the rest of the time – a higher rate than normal? And, if I have two meters (one of which I cannot find), how are the two meters tracking the THREE different rates? IE, the 24/7 off-peak for the shower, the 5-12 hours off-peak for the THTC, and the higher than usual rate for the cooker, etc? 3. Is the Ecodan ASHP system suitable for the THTC, or should I push for another tariff? From my scant understanding, the THTC is for storage heaters, does the Ecodan have storage heaters?! 4. Defrost mode, comes on quite a bit. Should I ask the installation company if the fan has de-icer, and if it does – does the defrost mode need to be one? 5. Is there a way to download the data from the FTC-5? 6. How do I calculate the COP, I tried to understand this two weeks ago and struggled! I think that might be enough! I have tried to make the questions succinct as possible, as I am finding the whole system a nuanced beast. As I said at the start, the forum has helped a lot already. I have duct taped a few drafts in the kitchen, and the front door. Update, during the time of signing up to this forum I received a reply from SSE answering a few of these questions – I will copy below, as I think it is good reference for others searching for info. re. THTC.