Unvented System or Replacement?

[Laurence737]

Hi Everyone,

 

The property we have just moved into has a Worcester Bosch Greenstar 24RI boiler installed that is around 5 years old.  It is a four bed house (around 200sqm) and we have a main bathroom and en-suite.

 

We need to get rid of the water tank in the loft so are looking at options to solve this.  We have come up with three potential options and wondered which would be the best option and pros/cons of each?

 

1. Replace the system entirely with a new heating system (combi or system boiler?) and remove the tank.

2. Would the 24RI be capable of running an indirect unvented cylinder? could we replace the current cylinder and tank with one of those?

3. Move the header tank about 4-5m from its current location?  I'm assuming if we did this we would also be best replacing the tank entirely for a new tank whilst we are moving?

 

Also the tank is a bit of a pig to get to (the house is a hall conversion and not a lot of the loft floor is supportive!) so would anyone eagle eyed know what material this tank is made of? where the photo is taken from would roughly be where the tank would move to.

 

Thanks a lot for the advice

[SteamyTea]

Looks like a plastic tank.

Just move it if all the holes are still in the right place.

If you use a vented system (looks like that is what you have), then there is no mucking about with certificates and annual checks of a G3 unvented system.

[Simon Brooke]

Simplest and cheapest would be to just move it. The boiler should have a few years of life left in it. The only issue for me would be whether you are happy with water pressure for showers.

[Laurence737]

Thanks for the replies, very helpful!

 

At the moment the shower pressure is ok, however the bathroom is currently on the ground floor and we are moving it upstairs, the en-suite is currently being installed so it doesn’t have the load of that on the system yet.

 

Which option would afford me the most pressure?

[PeterW]

UVC or Thermal Store will give you mains pressure, or a shower pump if you want to keep the current hot water tank (assuming it’s in decent condition and big enough) 

 

 

[SteamyTea]

36 minutes ago, Laurence737 said:

Which option would afford me the most pressure

It  is not pressure, it is flow rate.

In a gravity system, flow rate is affected by the distance between the shower head and the loft tank (what gravity does).  You may get away with larger bore pipes (probably easier to give it a go than calculate it).

I have a very cheap shower pump that works well.  Just make sure your cylinder and loft tank can cope with the flow, you don't want to drain the loft tank while using the showers.

Pumps are a bit noisy though.

[Timedout]

As PeterW says. Go for a vented thermal store, one of the combination types but avoid the ones with a plate heat exchange. You can have 3bar feed on your hot water and you do not need a Part G certified installer, annual inspection and you can put it in yourself or any plumber. Plus you won’t be replacing those crappy T&P valves when they fail as they frequently do. The thermal store costs more though. I am just about to do it on the place we have recently bought. I need a new boiler though as mine is a 1976 model.