I'm after some advice re. what to do next with our problematic electrics and/or boiler. A bit shameless, but I would really appreciate any pointers as I'm trying to not rack up bills bouncing from one trade to another.
My wife and I live in the ground floor flat of a victorian house in London. It was converted into two flats about ten years ago and since then we've found the odd quirk in the electrics and plumbing, but nothing major. Last Wednesday at about 11pm, while we were watching TV, an RCD in our consumer unit tripped. This RCD supplies the flat's three mains circuits, each with their own MCB - two 32A socket loops, the first of which includes the boiler, and one dedicated 40A cooker circuit. I could reset the RCD, but only after manually tripping the first MCB. This left us with one mains circuit, on which we are now surviving with the help of a few extra multi-ways and layers of clothing.
Upon inspection, the boiler had a small puddle underneath it. Maybe two tablespoons of water. Me, putting 2 + 2 together and possibly getting 5, what with the cold snap and our heating turning off about an hour before the RCD tripped, thought that the boiler had developed a fault due to condensation or a temperature-related leak. Drying out the boiler for a few hours using a portable heater seemed to allow us to reset the boiler MCB and the RCD, but I have no way of proving this. Whether the drying helped or not, what I have been able to do every day since then is deliberately trip the boiler MCB just before bedtime and re-enable it in the morning so that the heating is on when we get home from work. This stops the RCD being tripped while we are asleep or out and killing the fridge etc, and the boiler has run every day for 4-5 hours with no issues while I've been doing this. We've also disconnected every mains plug in the house, and I've also disconnected a short, double socket spur that was added a couple of years ago (the last time the electrics were altered). No effect on the RCD/MCB behaviour.
Make sense, so far? Still awake?
So... local boiler engineer comes out and immediately points out that the switch fuse should be 3A instead of 13A and the ground connection on the PCB isn't in place. Great, I think, but sorting those two things makes no difference. All basic meter checks are fine and the place where the water was dripping from is on the other side of the boiler to its PCB, which is bone dry. He notes that the MCB remains tripped even if the boiler fuse is removed, but I had already tested this myself and know that the fuse doesn't fully isolate the boiler from the mains circuitry. But he then rigged up a short mains lead and ran the boiler off a working socket on the other MCB for about 20 minutes in total, covering heating and hot water. No problem! :?
I agree with the verdict that we need to answer the electrical question before he can service the boiler confidently (he was actually really good to deal with), but it still nags me that the leak and the power cuts started happening at the same time. Am I missing anything? Apart from the unlikely rat-chewed-wire theory, the only common factor I can see is the cold weather, which might be causing some interstitial damp somewhere on that mains loop and also, by coincidence, a bad expansion leak (or similar) with the boiler. There are also the grounding points on the the copper pipework to consider, but I would have thought that these would be isolated from the boiler PCB.
Any ideas? Quite prepared to pay for an electrician, I just know that this forum has some serious brainpower! Thanks for reading.
My wife and I live in the ground floor flat of a victorian house in London. It was converted into two flats about ten years ago and since then we've found the odd quirk in the electrics and plumbing, but nothing major. Last Wednesday at about 11pm, while we were watching TV, an RCD in our consumer unit tripped. This RCD supplies the flat's three mains circuits, each with their own MCB - two 32A socket loops, the first of which includes the boiler, and one dedicated 40A cooker circuit. I could reset the RCD, but only after manually tripping the first MCB. This left us with one mains circuit, on which we are now surviving with the help of a few extra multi-ways and layers of clothing.

Upon inspection, the boiler had a small puddle underneath it. Maybe two tablespoons of water. Me, putting 2 + 2 together and possibly getting 5, what with the cold snap and our heating turning off about an hour before the RCD tripped, thought that the boiler had developed a fault due to condensation or a temperature-related leak. Drying out the boiler for a few hours using a portable heater seemed to allow us to reset the boiler MCB and the RCD, but I have no way of proving this. Whether the drying helped or not, what I have been able to do every day since then is deliberately trip the boiler MCB just before bedtime and re-enable it in the morning so that the heating is on when we get home from work. This stops the RCD being tripped while we are asleep or out and killing the fridge etc, and the boiler has run every day for 4-5 hours with no issues while I've been doing this. We've also disconnected every mains plug in the house, and I've also disconnected a short, double socket spur that was added a couple of years ago (the last time the electrics were altered). No effect on the RCD/MCB behaviour.
Make sense, so far? Still awake?
So... local boiler engineer comes out and immediately points out that the switch fuse should be 3A instead of 13A and the ground connection on the PCB isn't in place. Great, I think, but sorting those two things makes no difference. All basic meter checks are fine and the place where the water was dripping from is on the other side of the boiler to its PCB, which is bone dry. He notes that the MCB remains tripped even if the boiler fuse is removed, but I had already tested this myself and know that the fuse doesn't fully isolate the boiler from the mains circuitry. But he then rigged up a short mains lead and ran the boiler off a working socket on the other MCB for about 20 minutes in total, covering heating and hot water. No problem! :?
I agree with the verdict that we need to answer the electrical question before he can service the boiler confidently (he was actually really good to deal with), but it still nags me that the leak and the power cuts started happening at the same time. Am I missing anything? Apart from the unlikely rat-chewed-wire theory, the only common factor I can see is the cold weather, which might be causing some interstitial damp somewhere on that mains loop and also, by coincidence, a bad expansion leak (or similar) with the boiler. There are also the grounding points on the the copper pipework to consider, but I would have thought that these would be isolated from the boiler PCB.
Any ideas? Quite prepared to pay for an electrician, I just know that this forum has some serious brainpower! Thanks for reading.
