Heating + water pressure questions

BigDonnerz

Hi folks. I recently moved into a new home and had a couple questions about heating and hot water. It’s a conventional gas boiler with two zones – one for heating, one for hot water. Doing my best to find answers myself but I’m a bit of a noob so if anyone could answer them I’d really appreciate it.

Firstly, when we moved in a few radiators needed to be bled and equalised, which was fine. After that the boiler pressure was a bit low so I wanted to top it up but was unsure how. My understanding is that normally this is done with a filling loop connected to the boiler but I couldn’t see one anywhere. A plumber advised me that there was another way - there’s a copper pipe connecting the cold mains water to the hot water flow for the rads. On either end there’s a penny valve which can be opened to top up the water pressure, but only if the shower pump is on. Is this typical? It does work but I’ve never seen something like this and wasn’t able to find information online. When I asked the plumber for more details he just said that it’s because the system is pressurised which didn’t make it clear to me. If pictures would help I can share some.

Secondly, the shower pump has a switch in the bathroom and we’ve been switching it on when using the shower but knock it off after – is this actually necessary? I’ve noticed that when it’s on the hot water pressure in the kitchen sink is much better but I was worried that maybe it would use too much energy to have it on all the time or could be damaging in some way to the system.

Any help would be amazing. Thanks lads

Lenar3556

1) sounds like a closed system, but without the benefit of a decent mains supply to pressurise it when required, so the booster pump is a work around. Given the rare requirement it’s ok I suppose. I would be inclined to disconnect one end of the filling loop you describe after the job is done, and flush plenty of water through your sinks lest there be any question of a back feed into the domestic water system.
Incidentally the location at which the system is filled/pressurised is of little consequence.

2) most people would leave it on all the time, unless there was a fault. The pump likely has flow sensors and starts and stops as required. There is little by way of an energy consideration - I suppose your kitchen sink may go through more hot water if coming faster!

It would be good to see a photo of the pump.

BigDonnerz

Thanks so much for the reply, this is a big help.

I think you're right about it being a closed system – it looks like the cylinder is a Telford Tempest which seems to be unvenented. Weirdly though there is a cold water storage tank in the attic so I'm not sure where that fits in if it's unvented. The house has solar panels for heating water, so could it be related to that?

Great to hear we can just leave the pump on all the time. I tried to take a picture of it but couldnt get a good angle but there's seems to be two parts - a Grundfos CM 3-3 A-R-A-E-AVBE C-A-A-N and a Grundfos PM 1 15 (can't link cause I'm new). Going off the product descriptions it seems like these are general purpose pumps not just for showers?

booooonzo

you sure its a shower pump and not a whole house booster pump thats feed from the water tank in the attic and pressurizes your unvented tank?
I believe you are not supposed to have anything feed from the mains in Ireland only the kitchen sink and the cold water storage tank