Shower for low pressure h/w, high pressure c/w

There are two possibilities I would suggest.

1. A venturi shower. This transfers some of the energy from the high pressure cold to boost the low pressure mains. Some people have tried these and been very satisfied with the results.
2. A single impeller pump on the hot supply. I had one of these in a previous house. The hot water only is fed through a pump with only one input and output port. These are cheaper than twin impeler pumps and widely available. It is important to use a pressure balancing mixer valve able to deal with a certain degree of pressure imbalance in the supplies. These are also widely available.

Number 2 will provide better flow rates and will also boost your bath tap. Number 1 will be much quieter and should give an excellent shower. It may also be cheaper.

Christian.

A lot cheaper overall. Also it is worth having a phosphor descaler on the cold supply into the house, feeding all the house except the drinking water. These should be fitted in all hard water areas. Small scale deposits can affect a venturi shower.

Fit a combi off the mains. A good shower pumps is £200-250 plus fittings ect. A combi can be had for £400 in B&Q and then no tanks or cylinders. A win, win situation.

I would agree that a Combi is good for a shower - but a £400 one is not going to give a good shower - the Wickes 102,000 BTU item (Halstead) is £525 inc VAT and controls with a 2 year guarantee and DOES heat water fast enough for a good shower - so good in fact that its costing a fortune in gas and water as no-one wants to get out !

Nick

The Wickes 102 is a good boiler and delivers 13 litres/minute. A 28 kW BIASI from B&Q will give a good shower of that there is no doubt. The difference in price from a power shower pump to the BIASI is not that much, the Wickes

My point is that, going combi is not very expensive and gives much added value.

But what if you add fitting to that?

I had a bloke come round and give us a quote for replacing our current system (Baxi boiler / HW tank / CW tank in loft that I'd like to get rid of but need to find out if flat downstairs uses it) which would also require fitting TRV's on all the existing radiators. Unit he recommended was a Micro Genus 23 (5 rads at moment looking to add 2 more possibly, bath and separate shower) at the pricely sum of £2175 + VAT. I suspect the unit's under powered as we want one that'll give an excellent shower.

And what's with fitting these TRV's? At the moment we've got the older valves with the inflow and out at the same end of the rad, but have been told we can't keep these, which means drilling holes in my nice sanded / varnished floors and lifting more floorboards?

Rant over, actually perhaps I should have started a separate thread for this!

Leigh

There is fitting for a £250 Stuart Turner power shower pump, and you still have the tanks and cylinders taling up space.

The Microgenus 23 kW will give an excellent shower, it is the bath that will be slow. Virtually all combi's will give a very good shower. I have the 27 kW version which is better. Go for a Baxi 130HE @ 16 litres/min. More expensive but a good flowrate.

There is no reg to say you need TRVs when changing a boiler.

Yep, but fitting a shower pump is an easier diy job than fitting a boiler.

I'm probably going to go the combi boiler route - I'm looking at the Ravenheat condensing boiler that B&Q currently have for 479. I've only got a one bedroom flat, so buying the Baxi 130HE as suggested below is probably a bit over the top! Plan is to do the water plumbing myself and get a plumber in to do the gas hookup and commission the boiler. I'll probably drill the holes for the flue but let the plumber do that bit too. Since I can't find any documentation about decommissioning back boilers, I suspect the plumber will have to do at least the gas related bits of that too. Still going to work out a lot more than just the boiler cost though!

My plumber seemed to think I needed them too.... Didn't find any regulations, but my reading suggested that if you don't have TRVs you need some form of individual room control - i.e. motorised valves and a decent programmer, I'd guess.

Ben

Avoid Ravenheat combi's. They have a CSI heating and system boilers, which are cheapish and not bad.

You rate a combi by the flowrate. 16 litres/min from the 130HE. Fills a bath nice a quick. If you have showers only them a smaller, cheaper one will do.

OOI, why? And do you have any opinion on the Biasi boilers also sold by B&Q?

Indeed - showers only. I was perfectly happy with the Vokera Maxin 24e in my old rented flat - couldn't find any specs, but the new Linea 24 delivers just under 10litres/minute, though. I think I recorded closer to 6litres/minute coming through the kitchen tap though. It would be nice to be able to run the bathroom tap at the same time and still get a half decent shower though.

Ben

They are not very good.

Better design and quality.

You have answered your own concerns. The higher the flowrate the better. The Wickes 102 combi delivers 13 litres/min. Cheap, 2 yr guarantee and a good boiler. The 28 kW Microgenus is v good and "very" well specced, with even anti-scale and anti-cycle functions.

Any views on Worchester Bosch combi's (the 28KW models)?

Cheers!

Expensive. Not much else. Too many mixed views on this from total crap to super reliable.

Interesting, as I was quoted £500 less to get one of those rather than the Microgenus.

Cheers!

I can't see why as the list price of the Bosch is cheaper. The Microgenus is the smallest case sized combi available. The prime reason I bought it.

After Bosch bought out Worcester the quality went suspect. It may have settled.

The new Junior is probably the one they are on about. It is about the same price as the Ariston. The Ariston comes with a 2 yr guarantee on the boiler and 5 on the plate heat exchanger.