Crofter

On full length boards I find an extra pair of hands, or two, helps enormously.

With the Octopus trial it seems that you have to actually install your system and then send off your £250 and wait to see what they say. I'm not really in a position to make that commitment. Are inverters and diverters dropping in price too? I know the panels are virtually being given away these days but I'm probably only looking at a small system.

I'm seeing grid tied inverters and other kit on eBay at tempting prices. Other than the usual caveats about buying secondhand, is there any reason not to go down this route? E.g. I guess some installers wouldn't be happy fitting secondhand equipment? If I wanted to sign up for export, are there any standards/certifications that I should be looking for?

Funny thing is, the whole place recently went through a new EIC and the immersion setup was never mentioned.

That's an interesting idea, not really sure where to start though.

Of course I could swap out the 3kw immersion element for a smaller one, it's got all night to heat a 200l tank so probably doesn't need to be that big?

Funny, it says 13A on it... which it obviously couldn't handle!

Ideally I'd be setting it up with a WiFi enabled timer, so that it could run on the E7 off peak rate, and we could turn it back or off when we're away. Not sure how to go about this though.

Yup it was running an immersion heater. In theory it should have been sufficient for the current. This bodge only came about because the sparky didn't realise we had two immersions on the tank. I think I'll need to get it done properly...

Think I had a close shave here. Plug now replaced and I'm keeping a very close eye on it. Any suggestions for why this would have happened?

It's only 16A which explains why we didn't just put the second immersion on it. The CU is right next to the tank and has a couple of spare slots for MCBs so it's probably easiest to just add a new circuit.

Back when our cottage was being built, my otherwise very good sparky had a brain fart and was unable to spot that the UVC had two immersions. Consequently we ended up with one circuit wired from the CU (this is used for the upper boost element, with a 30 min timer switch). The bottom element ended up being run off the normal ring main, using a plug in timer. This is obviously far from ideal for a number of reasons. The simple mechanical timer will go out of sync with the off-peak time if it's turned off for any reason (e.g. a power cut). We've also had a couple of timers fail on us- I guess that although they're rated to at least 3kw, they don't actually like running a big current on a daily basis. Anyway I think it's time to upgrade this. 1) can the overnight and boost elements run off the same MCB on the CU? I'm assuming not, otherwise the sparky would have just done that at the time. 2) I see you can get MCBs with built in timers, with battery backup. Looks like a neat solution. Are they any good? 3) In an ideal world, I'd like to have remote control over the immersion, as we are away from the house a lot especially over winter, and we don't really need to keep the tank hot for weeks when the place is empty. We also have guests staying who can have a habit of running away all of the water, so the ability to remotely boost it would be useful (I'd rather have a higher electricity bill than a bad review!). What options do I have for a wifi-enabled timer that will be robust enough to stand up to a 3kw load every day?

I disagree. I think it's a knowingly unpopular move led by clear science on particulate emissions. But let's just agree to disagree on this.

Wood pellets never made sense. See also, cash for ash in NI

Are you talking about a vehicle heater? I've installed a couple of them in boats, they're good and powerful, for occasional use it might be a good idea. Main thing to watch out for is the exhaust which gets seriously hot and needs to be fed out of the building without touching anything flammable.

We have a house on THTC and we've had to move to OVO now. No word yet on the tariff coming to an end, but I've heard rumours from other parts of Scotland. If they do end it, my problem is that simply switching to E7/E10/standard won't be itself be an option. My heaters are controlled by the time switch, they do not have any timers they I can control. It's not going to be very fair on little old ladies with the same type of installation as me to expect to have to get a sparky to install the necessary timers/controls, out of their own pocket. Hopefully there will be some sort of grant to cover this.

I do hope it's implemented this way. Our local (SNP) MSP has been pretty critical about this. I wonder how much leeway individual councils will have?

The choice of heating system doesn't really affect the humidity (assuming you're not using some sort of open flame gas heater, which will spew out moisture). But the advantage of ASHP, of whichever type, is that they convert one unit of electricity in to three or four units of heat, so compared to basic electric heating you can have the house much warmer. Anything you can do to raise the temperature will help. In theory the air movement of A2A might help eliminate dead spots where damp air can linger. But if you under-spec the A2A you can end up with high airflow rates which will lead to noise and drafts. I'm in the process of planning an A2A install myself but can't report back any actual feedback yet...

Yes, it's a different version of ASHP. The outside unit (with the fan) looks the same. It's also the same thing as air conditioning, you're just running it in reverse. A conventional ASHP heats water for radiators or underfloor heating. A2A heats (or cools) air directly. They tend to be more efficient and easier to install, making them cheaper. The main downside is that there are no grants available for them. If you're looking for A2A heating, it's easier to just look for air conditioning, it's the same thing.

That's neat, but very expensive, and doesn't appear to take an AC input? Not sure what the balancing is all about for a DC immersion... I thought you'd just need to make sure it had enough volts and amps? I'm probably looking at a 600w DC immersion at 12v, so 50A draw. Use a Victron Battery Protect to switch it on and off according to voltage. Undecided on the battery, in theory any old lead acid would do but I imagine the system will work better with e.g. 100Ah LFP instead. But there goes another £200...

I'm kicking about some ideas for how to make a dent in my electricity bills without having to spend thousands on a big MCS approved PV/battery project. Currently have a direct UVC. Plan A: swap the existing bottom immersion element for a dual voltage AC+DC version. Wire up the AC side as usual, then DC side goes to a couple of panels, small battery, charge controller, possibly some sort of low voltage disconnect relay. Should be able to put something together for £250-£500 depending on how powerful I want it. Thoughts? Plan B would involve using grid tie equipment instead, but I don't see that coming in anywhere near the cost for my basic off grid approach. It would obviously have advantages though.

Plastic should be installed on the warm side of any insulation, to prevent moist air from entering the insulation and condensing as it reaches the cooler outside layers. Especially important in timber frame buildings, but it's always good to keep your insulation dry.

You can saw the bottom off a door though 😁 We did a loft conversion in our previous house, that was only 2m headroom. Sailed through the building warrant process without a hitch. That was in Scotland, in about 2009, well before this forum existed.

That looks very handy. Did you have a height limit for the PV?

The '3 caravans' allowance probably isn't going to help me much. I don't know if there are restrictions on who can stay in the 'van or for how long, other than the April to September limit, which would actually be ok for us. The main problem for us is that whatever we put on the site is going to have to stay there. I've made a rough footpath up the hill but it's hard to get as much as a wheelbarrow up it. I'm currently leaning towards the idea of a 12m² ground mount solar array (within PD) and then boxing it in. A bit smaller than I'd ideally like but I could make it work.