Temp

@Onoff & @Nickfromwales I think it started getting worse as the weather got colder but then again they aren't used much in summer. I was able to speak to the electrician briefly today. He confirmed.. Each heater is 3kW (approx 12.5A). The insulation breakdown tests he did recently passed ok He plans to change the RCBOs from C16 to C20s but might not be able to do them all. Think he said he needed to check the wire impedance to ensure they would trip if there was a short? He also mentioned he's considering investigating NTC devices to limit inrush. Ive used these before as auto resettable fuses at much lower currents. But not for high power applications like this. I know they can be a bit tricky to get the right spec. Dimplex who sold the heaters say they aren't made/supported now.

As I recall you have to walk around the room switching on each heater in turn so I don't think the issue is multiple heaters being turned on at the same instant.

You can either fight them or find out what bricks they approved on other new builds in your street. Make sure to tell them they are the same as already approved up the road. Ditto the windows.

I think it might be to stop a developer building a house, then just before fitting the front door they sell it to Mr Smith and agree the builder is actually building a self build for Mr Smith. They could split the CIL saving between them. Something like that. Requiring all the paperwork at the outset stops this.

The DT4 appears to be capable of either mains power with battery backup or just battery operation. The two outputs A an B do appear to be volt free. So based on what you said I think that ones OK. It does appear to be a bit simple. For example I don't think you can program it to drop the temperature a few degrees at night or while out at work but I don't know if thats appropriate for ASHP systems.

After some info/advice on breaker curves and/or soft start/in-rush limiting.. Our local village hall is having issues with its IR electric heaters tripping at switch on. There are 6 heaters each on their own C16 30mA RCBO. I don't currently know the wattage of each heater but it looks like they have 6 elements in each so I'm assuming they are quite powerful units. My background is in electronics rather than electrical engineering so I've just been asked to "translate" what the electrician is saying when they can get him to visit next time. For the moment I'm assuming they are tripping due to inrush current rather than Earth leakage but will ask if he's checked that. The wiring doesn't look too old. It looks like last time he visited he switched one of the RCBO for a B20. That one seems to be OK but three others on C16 are tripping. As I understand it.. C curve trip between 5 and 10 times rated current within 1 second. So a C16 trips between 80 and 160 A. B curve trip between 3 and 5 times rated current between 1 and 5 seconds. So a B20 trips between 60 and 100A. Q1: So tentatively it sounds like the issue is the duration of the inrush current rather than the magnitude of the inrush current? Q2: The whole lot are on one 100A RCD (I think) so I suspect he can't switch them all to B20 because 6 x 20A = 120A. They are normally all on at once so can't apply diversity? Or am I talking bollocks 🙂 Q3: Would it be reasonable to try 6 x B16 instead of C16 as they tolerate overload for a bit longer or am I misunderstanding how they work? Have heard conflicting info from the Village Hall committee. One said the electrician was considering adding in-rush current limiting at £25 to £100 per heater, but another added "or rewiring". I think each heater is on a 2.5mm^2 radial. Part clipped, part loose in the roof and part in metal conduit. I think a 2.5mm^2 radial is typically limited to 16-20A. Any suggestions for how to diagnose the problem ? Do electricians carry a fancy meter that can measure in-rush peak durations ? I suspect not.

+1 to what @DannyT said about temperatures. They can/should also use an additive in the mortar. Don't let them use washing up liquid. I forget what the correct stuff is called but it's not expensive. You could buy it for them if necessary. They should also cover up new/green work overnight.

I think he's forgotten. We have our kitchen sink on an interior wall. Builder ran 110mm through the foundations and up through the floor. Adaptors down to 40mm.

3bar is around the pressure at which the PRV will open so I'm inclined to think there is an issue with the expansion vessel. Faulty, not pumped up enough or too small.

I've used one of these T201 for a few years but it's GSM so needs a pay as you go SIM. https://www.ebay.co.uk/itm/126282422240 You can set alarm thresholds or interrogate it to ask the temperature. Has outputs so you can connect to heating system or fan heater (I think).

See reply by @ProDave Plan ahead to make the join work.

Sorry to contradict but I think they can put foundations on your land.. https://www.partywalladvice.com/2010/01/27/can-my-neighbour-project-his-footings-over-the-boundary-without-my-consent/ You can try and tell them that it's not necessary because they can build "Eccentric Foundations" (egwhere the wall doesn't sit in the middle of the foundations.).

Some possibilities.. 1) Once a Pressure Relief Valve opens once they have a tendency to leak and let water out too easily at a lower pressure than its rated for. The more it leaks the more easily it leaks. Not sure why? Perhaps they are sensitive to a bit of grit or scale in the water. I've seen it a few times. 2)The Expansion Vessel could be faulty allowing the pressure to increase too much when the system heats up. Monitor the pressure and see what happens as it heats up. Perhaps check the valve on the Expansion vessel. When pressed air should come out not water. 3) The filling loop could be letting water into the system when it's meant to be closed causing over pressure. 2 or 3 could cause the PRV to open then it sticks open due to 1).

+1 Tiles and flashing should collect all the water. Membrane is just a backup.

This link is talking about the consequences of renting out a new property (instead of selling it) on the VAT you pay or reclaim when building it. I don't know if the HMRC Information sheet referred to below is still current. It probably doesn't apply if you intend all along to rent rather than sell. There might be a way around it by selling the property to another company you set up to rent it out. The sale is zero rated rather than exempt and that can make a difference. Seek advice on this issue. https://www.bishopfleming.co.uk/insights/vat-consequences-interim-rental-new-residential-property Quote.. With the recent slowdown of the housing market, many developers are considering interim rental of new residential units, to generate revenue pending finding buyers. In this article we explore the VAT consequences of this, and ways to mitigate the VAT cost. Where a housing developer has constructed new houses or flats, or converted non-residential property into dwellings, and they are intended for sale, the VAT incurred on the development can be recovered in full (except some fit-out costs like appliances on which the VAT is blocked). The VAT in question is often VAT on the land or property if incurred at purchase, and the legal and professional fees etc. This can amount to significant amounts of VAT. For VAT purposes, interim rental represents a change of use of the property from the intended zero-rated sale, to exempt rental. Exempt use does not give a right to recovery of related input VAT. This could potentially result in clawback to HMRC of all the VAT recovered. However, in the last slowdown in 2008 HMRC recognised this could produce an unfair outcome, and issued a VAT Information Sheet saying that where the developer retains an intention to sell the properties, there should be a fair and reasonable adjustment to reflect both the temporary exempt use and the intended sale. This policy has been included in HMRC’s current internal guidance so should remain available to use. In most cases it should result in a smaller VAT clawback and can result in no adjustment if the amount is small enough to be below ‘De Minimis’ levels. However, the amounts can be complex to calculate, depending on factors such as the length of the interim rental period and expected sales value, both of which may not be known or difficult to evidence. Another option to consider is whether the new residential properties could be sold to a group company prior to the group company renting them out. For VAT purposes this can fix the zero-rated first sale of the property by the developer, and secure the VAT recovery on its development costs, but needs to be considered alongside wider commercial, legal and tax implications including SDLT and Corporation Tax etc. If you are considering interim rental of new residential property pending sale and would like to explore your options, please get in touch with our VAT team.