Recent content by DIYknot

@SUNRAY I'm not sure what your point is. You say you've seen steel conduit pull screws out on long runs, which is understandable if the runs were very long and the screws on the fixing brackets were too tight against the conduit, so preventing it from moving. However, this is a situation that...

True, but the coefficient of expansion for PVC is much more than for steel so it expands more for a given temperature rise. For steel the coefficient is 12E-6 so for a 10m length changing in temperature from say 0 deg C to 40 deg C that 10m would expand by just over 4 mm if allowed to. For PVC...

That's an American standard though. This work is in the peak district in the UK. We have far more jobworths over here:giggle:

Yes, I have the regs books, hence my comment about P . Section 2.5 quotes Reg 12(6A) and says that the 'installation of a new circuit' is notifiable but the definition of 'a new circuit' rather depends upon where you look and nowhere does it define "reasonable provision" But with regards to my...

Yes, that's exactly what I was thinking. In the past when I wanted a more or less waterproof but sliding fitment for another application I coated the pipe in petroleum jelly and put silicone sealant in the socket. That way the sealant stuck to the socket but not to the pipe and created a...

About 25 m horizontal (ish) in total with a horizontal right angle bend about half way. One leg will be on a wall with half of that covered by ivy. So I could have a couple of 10m runs. Why do you say steel causes more issues?

I'm planning to run some 20mm PVC conduit along an external wall to supply power to an outbuilding. I appreciate that when run externally the various conduit fittings should be glued on to prevent water getting inside the conduit (this is in the peak district so there could be a lot of water...

A 'proper professional' should be qualified enough to understand the physics of what they do , be willing to explain it to support their view and question it when necessary. They would not simply be abusive and dismiss the Consumer Council's analysis of several hundred customer's views on the...

Thank you for taking the time to give a very well considered answer to my question. Just the sort of thing I was hoping for. Unfortunately I was aware when asking it that I risked getting some abusive or knee jerk reactions from those who just carry on doing what they've been taught or what...

Interesting you say that. The boiler I am getting is a Worcester (the only manufacturer recommended by Which? magazine. They say in their small print that you need a flow switch with nearly all of their programmers. That would seem to make sense.

I'm really grateful for all these comments, thank you I thought compromise might have something to do with it. When a fitter said 'you have to have a room stat to comply with the law regarding interlock regs and energy saving' but can't really explain 'how' the room stat did it, nor why it...

But doesn't that rather defeat the purpose of central heating. I'd like my hall to heat up just as quickly as other rooms - just not necessarily get to the same final temperature. As far as boiler interlock is concerned though, surely throttling the rad to reduce the rate of temperature...

Thank you very much for replying so fast but I still seem to be missing something. If a system is correctly balanced it doesn't mean all locations are at the same temperature. It simply means that the lockshield valves on each rad have been adjusted so that the rads further away from the...

So once the hall is at 18 degrees everything else shuts down and other rooms don't get heated regardless of TRV setting. I can see that saves energy, but so would just turning off the boiler <grin>. In this situation there seems no point in all the TRVs since the hallway decides if, for example...

I understand what boiler interlock is and how it prevents dry cycling but please can sombody explain to me HOW boiler interlock works when used in a system where every radiator has a TRV and one location has a room stat. (I've been told to fit a room stat as well as having a TRV on all rads to...