Russdl

Alternatively, find the nearest location to you on the Weather Underground map https://www.wunderground.com/dashboard/pws/ILONDO538 and that will be a personal weather station near you, probably in someone’s back garden, and that should give you a better idea of the local air temperature. if the temperature defaults to F you can change it to C, settings are accessed via the three bars, top right corner.

Preventing the heat getting in is a great plan, but don’t open up to ventilate until the outside temperature is below the required indoor temperature. If it’s pushing 30 degrees outside after when you open up to ventilate it will soon enough be pushing 30 degrees inside and your shading would have been for nought.

Crikey, that was a long story and similar to ours in some respects but so wildly different in others it must be a completely different situation. For example, I got on very well with all visiting trades - except for one who was described to me as a high functioning sociopath (I had to google that, but it is absolutely spot on). The distribution board in the photo looks just like ours except for down in the bottom right hand side. In those images ⬆️ there are 2 MCBO’s not connected to anything. In our distribution board those 2 MCBO’s are the power for the two Willis Heaters ⬇️ work that was completed on the 28th Nov 2020. Another major difference is you say you’re owed £1100. We are owed £4787 in an unpaid CCJ so clearly a completely different situation. The Last time I looked there were 3 unpaid CCJ’s against the individuals Limited company totalling £26,887, I can post images if you’d like? That may have changed by now but I can’t be bothered to spend another £8 to check, it may be a worthwhile investment for others?

The original electrian sourced by the M&E contractor was a top notch professional I would say. When the original electrician became unavailable the seemingly less professional replacement was parachuted in. On the face of it you wouldn’t know the difference, under the covers the difference is more obvious. Thanks to the wonders of modern technology (phone cameras, text messages, emails, site diary etc) I know exactly when this wiring was done and who did it. Just looking at the wiring in the distribution board you can tell this wiring was done by a different electrician. The original electrician’s wiring was incredibly neat and ordered, the replacement electrician’s work not so much. Perhaps he wasn’t fully qualified? It never crossed my mind to ask.

I’ve just pulled the damaged contactor apart, the burnt terminal is done up as tight as a tight thing - there is no way there was ever a cable clamped in there. It must have just been wedged along side or something? The red arrow is pointing at the heat damaged terminal (obviously!!) in the fully closed position, the green arrow at a fully open terminal (with only minor heat damaged). I can’t believe this, I can’t get my head around how a professional electrican could leave wiring in such a dangerous condition.

Well it’s all back together and working, nothing has gone bang and nothing (apart from the Willis heaters!) is getting hot. I think I’ll chalk that up as a good result. ~~~ I’ll keep hold of these two in case the installer or his boss wants them.

You’ve got to start with external shading, prevention being better than cure and all that. East/west windows could be equally problematic. I’m sure you’ll be building with high levels of insulation and air tightness, in which case I would have thought that without shading/cooling the recent brief heatwave would have been unbearable. We have no cooling per se but we do have external blinds, the last few hot days have been a non event as far as internal temperature/comfort goes but that does require a very much non automated heat purging strategy of an evening (opening doors/windows, ramping up the MVHR etc).

I’ve got the new contactor now but before I start putting it all back together again is it ok that the top of the contactor junction box (for want of a better name) has been cut out? I was under the impression this shouldn’t happen. This open end is mounted snug to the distribution board, so it’s not open to the elements/fingers etc.

No, I’ve replaced the obviously burn T&E and that ends up at the right hand Willis heater that wasn’t working.

Likewise, I’m confused. Something I hadn’t spotted before, in the first picture I posted on this thread ⬆️ where I was concerned with the overheating on the right hand contactor you can clearly see the light blue neutral into the left hand contactor is definitely not properly inserted. I can’t understand how the Willis heater was working and, as you say, why that left hand neutral wasn’t all burnt and crispy like the right hand neutral?

I’m amazed and confused. I’ve just removed the good contactor and was stunned to find the neutral for the Willis heater did not appear to be connected at all, and this is the one we normally use. I thought I may have dislodged it but looking back at a photo from a week or so ago, despite the shadow I think it’s fairly clear to see that the neutral is not properly inserted into the terminal. How on earth did this Willis heater work? I guess the neutral must have been just inside the terminal and just tight enough to stop overheating but not tight enough to stop it coming out completely when I removed the contactor?

I thought I’d try and tidy up the numerous cables in and around the contactor whilst I await the arrival of the replacement. It looks like the electrician used a machine gun to attach a couple of back boxes to the plasterboard during the original installation and then used some bloody great big screws to attach the junction box. At 70mm those screws are just the right length to go straight into the airtight layer. Nice. None of the above is the end of the world but on top of the poor/dangerous contactor installation it is mildly annoying. Anyway, all the heat damaged T&E is now replaced so I’m pleased about that.

Thanks for that detail Dave, mildly alarming though it is. I’ll definitely be in the market for an electronic nose to sniff out any future problems. As nothing trips out, what would have made the connection fail in the end? Is it just a build up of crud on the neutral wire?

That contactor did get really hot. How come nothing tripped off? Is that indicative of other problems? T&E from the contactor to the Willis heater switch easily removed. ~~~ The terminal screw is at such a jaunty angle I can’t even get a screwdriver on it. The electrician must have been aware what was happening. Surely?

Thanks 🤣. Im not afraid, I can’t do any worse than the professional that went before me! I just want to ensure that any rectification/replacement I do is done according to best practice.

That’s what I’m here for, “HO’s”. I’m no electrician so I’m seeking advice. I’m definitely going to replace the contactor, I’ve no idea how damaged that is internally but it has most definitely got very hot and, on balance, it would seem that the whole length of T&E should be replaced as well, so I’ll do that.

Just so I’m clear on that advice you say the Wago would be fine? I do. But I guess the electrician that did the original install didn’t. However tugging upwards against the distribution board would have been difficult I guess.

Good point, I’ve not had a good look at what that would entail, replacing the T&E from the contactor to the fused spur, but I suspect I could do that with relative ease.

During my mid year service of the house it turns out that the second Willis Heater we hardly ever use doesn’t work anyway. After a bit of investigation it became pretty clear why that was. The neutral from the Willis Heaters fused spur into the contactor was trying to catch fire, it had actually melted and stuck to the outer casing of the junction box. The neutral was in the right hand No.3 terminal - kinda. I found that pretty disturbing, especially as there was no indication of when this had happened (nothing tripped off, no smoke alarm) or how long ago it happened. On closer inspection I think it’s clear what has happened, the terminal screw seems to be cross threaded so I guess it felt like it was done up tight but clearly it wasn’t. Stuff clearly needs replacing, like the contactor and the Wago. The obviously burnt twin and earth needs replacing, can I just cut out the burnt sections and splice in new cable with these? Or should I replace the whole length to the fused spur? The T&E appearing above the contactor is directly from the distribution board and looks slightly heat damaged, I guess that all needs replacing as well? As a side note, I’m going to be sourcing another smoke detector for this area. There is a smoke detector in the room and also an MVHR extract. The problem is with the relative positions the MVHR extract will effectively prevent any air from the area of the distribution board passing over the smoke detector.

No such thing as a dim question (Joe90 RIP would have told you that) Currently I have 2 tariffs when I buy, cheap overnight expensive during the day. I fill the battery on cheap rate and the battery runs the house for the rest of the day. I buy almost nothing at the higher rate. The particular tariff I’m on was dependent on having an EV (hybrid in our case) When I sell it’s fixed, whatever time I sell it. Excess PV during the day or offloading the battery when I don’t want so much in there. All of this is likely to change when it suits the supplier which I guess is fair enough because we couldn’t survive a winter without them.

Pre battery and hybrid car we were consuming 7.5 to 8.5MWh annually, the figures are a bit skewed now as we’ve become something an energy trader and EV user, 2024 consumption was 14.5MWh. Regarding what? Tariff or battery? Tariff: I guess you’ll have to see what’s out there in a couple of years time, I’m sure they will continue to evolve. Battery: I’m very happy with the GivEnergy AIO, in the event of a power outage we could run the whole house indefinitely on the proviso that the days were sunny.

I was about to say that I’ve been ‘Top Trumped’ again! But I guess the RHI payment makes it an uneven playing field so maybe I haven’t? Mind you, I was on a flexible export tariff post Covid and post Russias shenanigans where I was getting crazy amounts per kWh at times - perhaps it is a level playing field.

It is pretty sweet isn’t it. I keep checking I’ve got the calculations right because I can’t quite believe it myself - but it is right. No, Sunamp here and it’s still going strong. (so far).

We have 7.44kWp of PV. 13.6kWh battery storage and use Intelligent Octopus Go/Outgoing Octopus. PV keeps the battery topped up and then all excess goes to export. The battery charges during the off peak window and runs the house for the rest of the day/evening. Prior to the off peak starting again we export what’s left in the battery to the grid, and then fill it up again in the off peak window. I've never been overly concerned with ‘pay back’ (which is why I drive the car I want and not the one that will suffice) but I suspect we’re on track to be paid back before all the kit is dead and needs replacing. Obviously very much dependent on future tariffs/sunshine. We’ve been in for 3.5 years and as of this month our total energy costs for the whole 3.5 year period around is -£30. To be exact it has cost minus £32:76* to run the entire house for the 3.5 years we’ve been living here, including 12 months of running a hybrid. *that figure includes the £400 bung from the taxpayer which we passed on to some local old, cold people. 😇

Thanks @Adrian Walker I’ll give that a miss then.