Central heating and hot water query

Beeblebr0x

I have a condensing boiler with a hot water tank and a cold water tank in the loft.

I have a pump so that I can get a decent water pressure in the shower. The pump isn't ideally situated as it's next to the party wall and the neighbours can hear it. There's nowhere else to put it.

My plumber said there's a way to pressurise the system by adding some extra kit, so in effect I'd have a hybrid system. When I expressed interest, he said he'd be reluctant to install it in case pressurising the system caused a leak, which in turn would mean the boiler would fail to operate due to lack of pressure.

We have a solid kitchen floor and everywhere else is new laminate flooring, so I'm loathe to take up any flooring.

My question is: is there a way to test pressurise the system to see if the pressure can be maintained? I know I'm risking a leak but it would save asking the plumber to go the whole hog.

FreeBear

Beeblebr0x said: My question is: is there a way to test pressurise the system to see if the pressure can be maintained? I know I'm risking a leak but it would save asking the plumber to go the whole hog.

The existing system could be pressure tested first. Either by connecting a pressure gauge to a pipe and then pumping air in - Not a good idea, as if anything lets loose, it could do a lot of damage. The alternative is to use a small hydraulic hand pump to build up the pressure. Any plumber that does UFH heating should have one in their van.

In both cases, the feed from the tank and the vent pipe would need to be sealed which may not be easy. And should a leak appear anywhere in the system, it would need to be fixed before you can use the hot water again.

Beeblebr0x

^ Hmm, good point about the feed and vent pipes.

Albermarle

AIUI, a leak is unlikely ( although possible).
We changed from a vented system to mains pressure and we have have never had a leak/pressure loss.

Beeblebr0x

One thing I forgot to mention is I have quite a bit of plastic piping instead of copper under the ground floor. I assume this is push fit, so I'm wondering if any joints would come adrift in a pressurised system?

FreeBear

The fittings and pipe will be rated for 3 Bar minimum and possibly tested to 10 Bar - Well above the pressures you would expect to see in any domestic installation.

Beeblebr0x

Thank you. Worst case scenario is I spring a leak under the ground floor and have to take up all the laminate to find it 😁

Albermarle

Beeblebr0x said:

Thank you. Worst case scenario is I spring a leak under the ground floor and have to take up all the laminate to find it 😁

With a mains pressure system, if the mains pressure is very high in the area, a pressure reducer is used to keep the pressure at max 3 bar. 
So if you speak to the plumber ask them what pressure they plan to increase to. Obviously the higher it is the more likely to get a leak. 

Grenage

How is the pump installed? Why is it so loud?  Can you post a picture?

Beeblebr0x

It's mounted on a breeze block and sits on an acoustic mat. I did a crude decibel check with my phone and the level agrees with the manufacturer's spec. I don't think the flow can be adjusted but I could be wrong.

ThisIsWeird

Isn't there a flow control on your actual shower? If so, what does the pump do when you turn it down?