Need advice on hot water pump or HWC replacement

[paulgraham]

Hi all,

I am in the process of planning a bathroom refit. In trying to decide what type of shower to have, I've opened a real can of worms.

I want to end up with a really nice powerful shower and the ability to have at least two relatively long showers in quick succession and I want the shower to look good and don't really want an electric or power shower (i.e. box on the wall).

My current system is fed by a very old Potterton Kingfisher II boiler, feeding a Fortic type 3 combination unit HWC (in the airing cupboard on the first floor, bathroom also on this floor), which has only 110 litre hot water capacity. As you might expect, the hot water pressure is non-existent.

What I really need is advice on what route to take to get a really good hot water pressure and do it in the most cost effective way!

Is it worth considering replacing the boiler as well in any refit? The boiler seems to be still going strong, but I do wonder how much life is left in the old girl; therefore as I would be getting a professional to do this work it might make sense to save a bit on the labour cost by doing this at the same time.

I'm a completely unwise in the ways of plumbing and don't know what options might be available to me, so your help is much appreciated.

All the best,

Paul

 

[gas4you]

The cold feed tank of a standard fortic tank is not really large enough to sustain the 'pull' of a good shower pump, plus shower pumps tend to be very noisey

If you have good cold mains pressure and flow, ie 20l/m and 3 Bar plus then either a good combi around 37Kw or an unvented HW cylinder fitted by a G3 registered installer would be your best solution.

Have a look at the Vaillant Ecotec Plus 837 or 937 storage combi as a possibility.

I never advise a customer to replace a boiler unneccessarily unless it is in a kitchen that they are re-fitting, then I advise to include the new boiler in the kitchen cost, otherwise sods law says that the old boiler will pack up after a couple of years and you will have a horrible space where the old one went, especially as in your case with a floor standing model.

 

[Agile]

You need to replace the hot water cylinder with one with enough capacity to cope with your demand.

I would suggest at least 210 li which will double the storage.

To get a better flow rate you can use a shower pump.

Be aware that a high pressure pump will use a lot more water, be more expensive to use and deplete the store much quicker.

Tony

 

[paulgraham]

Many thanks for your replies gents.

I would rather not replace the boiler, so I think the replacement cylinder is the way to go.

Is anyone able to give me some recommendations of cylinders to go for, taking the Kingfisher II into account?

I do have what I would call excellent mains water pressure, although I couldn't tell you the actual pressure rating (can anyone tell me how to calculate this?) So perhaps an unvented cylinder is the one to go for??

I was also looking at the aqualisa thermo range of showers and maybe even the digital ones, does anyone have experience and thoughts on these?

 

[Doctor Drivel]

You have two optimum options:

1. Replace the boiler with a high quality high flowrate combi The Vaillants have been mentioned and look at the Atmos as well as others like W-Bosch, Viessmann, etc. The boiler you have is inefficient and eats the gas. This gets rid of the Fortic releasing valuable space. Much lower gas bills too, so worth considering.

2. Keep the Fortic, but replace the boiler with a combi. The combi heats the Fortic in the same way with the same valves etc. The combi does not need to be a high flow model, a cheaper low flowrate model will do as they all do showers well. Then have the shower only off the combi to give instant and endless DHW. Have all other DHW taps off the Fortic. You end up with no expensive and noisy shower pumps, a fast bath fill and a new cheaper to run boiler too. Having only the showers on the combi means it will be more reliable as the DHW section will only be used once or twice a day, and no constant on-off due to taps in the house being turned on and off.

Note: Avoid an unvented cylinder, as these are expensive and require an annual service which costs. The cost of an unvented cylinder would be more than a combi that serves only the shower and your gas bills will still be high, so little gain except a higher pressure shower, that will empty the cylinder eventually. Put in a combi, keep the Fortic and you win all around - and cheaper bills, endless high pressure showers and a new boiler to boot.