Recent content by achrn

My understanding is that it will be lagged - I dived in to photograph it before that was done. The primary flow and return under floors and in walls are lagged already. The wiring is being re-examined so probably will get moved - the electrician put that in (to suit the previous chap's valve...

Can you clarify which pipe? I don't think there is any corrugated pipe, but I might have overlooked something. There is very slight rippling on the inside of a couple of pipe bends, but it looks much worse in the photos - it has just caught the light.

OK, thanks all. I'll talk to the plumber about the things noted. With respect to costs - I don't know what the builder is recovering from the first plumber, but he was talking about recovering some.

Recap: I'm having an extension built with new boiler and complete re-plumb. I was slightly worried about the competence of the builder-appointed plumber. I asked for advice here and subsequently became very worried. Eventually the plumber was kicked off. The full detail (all 20 pages of it)...

I think the plumbing work is done. There's some wiring sorting out still to do.

after teh first plumber was ejected, and a new plumber was appointed

I've got one sat here that's not controlling anything, so I just put it in the fridge for you. In 20 minutes it dropped from indicating 21C to 12C. Having taken it out, it took 3 minutes to go back up 1C to 13C, but in the next 2 minutes (ie, now 5 minutes since coming out of the fridge) it...

Yes, I've got (and checked) Gas Safe number, I haven't checked his unvented, he's promised that I'll get that before he does work to the cylinder (at the moment he's fixing other stuff).

OK, I think this is resolved. Thanks all for your help and suggestions. I've been at the house for about hour this morning with the newest plumber and gone through everything he proposes to do. This chap was quite happy to show me his registration number (and I've checked that at gas safe)...

Yes, I said 480 l/sec when it should have been 0.48. I said I was looking for 20kW and the figures suggested 1.5 m/s. But ha ha you've found my figure implies 20,160kW and 1,500 m/sec While you could have just said "yes you got the numbers right, but you've dropped the decimal point out"...

Is that a sensible proposition? It adds a failure-prone component, so will add to the long term maintenance burden, but presumably not by much. More significantly, will the boiler pump be able to pump through the second pump when the boiler us trying to over-run and the second pump is off...

As I understand it: By the table in BS EN 12828 at the flow necessary to match the boiler output the available pump head is 'used up' between boiler and valves (plus the equivalent length of return). There's no head 'spare' to drive water through coil or the radiator pipework, so flow rate...

If I add up radiator and heater outputs (I've guessed for the three towel rails, I've got the manufacturers figures for the rest) I get 23.3 kW. The cylinder has a 20.5 kW coil. Do you size on adding these up? In that case my system can more than consume the boiler capacity. For the...