nikbower

Brilliant, thanks all. As the boiler will be directly above the UVC, I think probably no more than 2.5m away - and we'll lag the pipes. Appreciate your help!

Just the question above please - if I put the boiler in the room immediately above the UVC (ie on separate floors of the house, but one directly above the other) is that OK? Will it be more difficult to service them? Thank you!

Right! I see that information for Gledhill - 17 minutes at 80 degree flow and 22 mins at 55 degrees. But that is for heat-up to 50 degrees, whereas the 32 mins given as time to heat the standard cylinder is for heat-up to 60 degrees and it doesn't say at what flow rate... I wonder how different they are on a like-for-like basis. OSO doesn't seem to provide the same information on their cylinder

I'm looking at cylinders designed to work with a heat pump. They give a re-heat time, but isn't that the time you'd expect if running them off a heat-pump? I thought the idea of coupling that design of cylinder with a system boiler was to get a much quicker reheat... but they don't seem to have that information

Hi there. Do you know whether it's possible to connect a system boiler to OSO Delta Geocoil in X Plan? Their brochure only mentioned S & Y Plan wiring... The coil in the OSO Delta Geocoil is rated 32kW. If it's paired with a 30kW system boiler, do you know how I work out the reheat time for the cylinder? This cylinder only comes with a 22mm DHW outflow connection. From the point of view of maximising flow rates, how much of an issue is that likely the be vs a cylinder that has a 29mm outflow? Thank you!

Do people generally agree that best approach is to install a condensing system boiler with weather compensation plumbed in X-Plan for PDHW and couple it with an unvented cylinder for all DHW? Or is there any dissenting thought on this? And is the idea of using a large-coil cylinder designed for ASHP one that everybody agrees on? Then I guess it would make sense to install both the boiler and the cylinder on the 1st floor bathroom and run all DHW and CH from there? Pipe runs to the LG for kitchen hot water and UFH will be longer, I guess.. Is there any consensus on which brand of UVC is best? From web searching it seems a lot of people have trouble with Joule and Gledhill (the cheap options), most people don't like Telford (which is actually what I have had for the past 10 years with no issues). Seems like OSO always highly rated, also seen love for ACV (which I've not heard of before). Worcester Bosch? Thanks!

Thanks John, I will read this carefully. One question, are you suggesting pairing a gas system boiler with a UVC that's suitable for use with a heat pump, so that a low temp output from the boiler can heat the UVC? Just checking because I won't be able to install an actual heat pump (conservation area and no outside space).

Hi there, I am moving into a terraced Victorian house on 5 floors, and I'll need to redo the plumbing and heating entirely. There's a 3-storey outrigger in the rear with floors set below the LG, between LG & UG, and between UG & 1st. The water comes in at LG level. Layout will be kitchen/diner on the LG, guest WC in the LG/UG outrigger, one bathroom in the UG/1st floor outrigger, another on the first floor and a third on the top floor. There are six of us in the house (we have four boys, aged 5-14). So the hot water demand is pretty high. In our current house we have a 300l unvented cylinder and we regularly run out of hot water (though mainly I think because it's a horizontal cylinder that's been installed wrongly with the hot outlet and cold inlet on either side instead of top and bottom - ie it was installed 90 degrees out of whack). Anyway, this is what I'm thinking and I would be very grateful for any advice. - Upgrade water supply to 32mm MDPE, install a 32mm stopcock reducing to 28mm copper pipe (like this?). - Run 28mm cold supply directly from the stopcock to an unvented cylinder in the 1st-floor outrigger bathroom. I am thinking 400l. - Immediately after stopcock, tee off 28mm cold supply to a combi boiler on LG, from which: the hot water side supplies the kitchen tap. That way the kitchen tap would not drain the unvented cylinder – and given its proximity to the boiler, the water should run hot more quickly than if it’s drawn off the unvented cylinder upstairs. What diameter of pipe should run hot water to the LG kitchen tap? The heating side is set up with three zones to supply (i) underfloor heating in the LG floor (two port valve); (ii) rads upstairs; (iii) heating coil for the unvented cylinder - Then the unvented cylinder would supply the UG floor cloakroom (also in the outrigger) and the three bathrooms. What size of combi boiler required to do this efficiently? Thank you!

Thanks very much! No chimney breasts remain, sadly... I'll check for air bricks! Heading over to the plumbing section now...

Hi there, I'm planning the renovation of a terraced Victorian house in London and looking for some advice along the way. All help gratefully appreciated! My first question relates to plumbing. I guess I should find the right area of the forum and post it there? Thanks! Nik