Comments on: Can I use a combi boiler along with a pressurised hot water cylinder to minimise pipe run in the house?

By: Kaley Sandhu

Kaley Sandhu — Mon, 12 May 2008 00:36:22 +0000

Yes U can…I have installed a combi running heating in whole house and ground floor hot water and an unvented megaflo running the hot water for the rest of the house. You will need to install this on an S plan ie: 2 2port valves or a Y plan..1 3 port valve. U will also have to wire in programmer and room stat..This is a good set up if you know how to install it.
If you install unvented cylinder make sure you get a balanced cold feed so that hot and cold pressures are the same for maximum performance espesially with thermostatic mixer showers…..GOOD LUCK

By: Aryana Harwood

Aryana Harwood — Thu, 08 May 2008 12:13:02 +0000

You can do that, fair bit of messing about, and remeber that the combi or unvented system can only produce an amount of water eqivalent to the mains input, for example, if you get 16 litres per minute, that is all that can come from the taps, ie 8 from cold and 8 from hot, if you try to run a bath and shower or washer or anything else, it will detract from the pressure upstairs, dependant on how many bathrooms you have, and what you intend to draw off, it can still sometimes be better to use a gravity fed system for the upper floors.

By: Flor Phipps

Flor Phipps — Wed, 07 May 2008 04:18:27 +0000

If I were you I`d go for the unvented cylinder and a system boiler option. The reason : you will get mains pressure hot water throughout the house, so, no need for power showers, You will still get hot water from an immersion heater (if you fit one in the cylinder) if the boiler breaks down and the quantity of hot water you will get will be far in excess of that which any combi can supply.

By: Kenna Tait

Kenna Tait — Sun, 04 May 2008 04:50:21 +0000

Yes you can, You will need to fit a zone valve on boiler flow independent of heating, also a cylinder stat this will control the zone valve, it’s not that difficult if you understand how it should work. or a competent engineer will be able to do it, i have used this method on a house with kitchen one end & bathrooms the other.

By: Lizeth147

Lizeth147 — Sat, 03 May 2008 16:52:44 +0000

You can do it but i wouldn’t bother, just get a system boiler and a bigger unvented cylinder. It would cost you a fortune in electricity bills to heat the cylinder otherwise.