New bathroom with old back boiler - considerations?

[DIY10291]

Hi, I have a very old bathroom with a very old central heating system, back boiler in living room with hot water cylinder upstairs and cold tank in loft. Currently, the bathtub and toilet are tank fed, and the basin cold is mains fed. I am getting the bathroom ripped out and replaced. What considerations do I need to make so that when the rest of the heating system is (soon) replaced, I don't have to replace the pipes in the bathroom?

- I have bought a shower with min. 0.5 bar working pressure - I am hoping the gravity system is sufficient (doesn't need to be good) to tide me over
- Should the current setup of mains-fed cold basin and tank-fed toilet and bath be maintained?
- If the bathroom is plumbed in standard 15mm copper pipe, then when the boiler is eventually replaced to a combi (and moved to the kitchen, and the radiators in the house replaced) will the bathroom just be fine as is? As I think the shower and taps I bought are the same as I'd buy if I already had the combi

Thanks

 

[DP]

While the Baxi Bermuda, assuming thus is what you have as other back boilers not as common, sure is now dated, but it needs a thermocouple and a regular service, which does not break the bank

If this was my gaff and I was short of money, fit better controls and an unvented cylinder
An Intergas boiler working as open vented another option but the two yearly deep service is a rock round the neck

 

[Madrab]

What considerations do I need to make so that when the rest of the heating system is (soon) replaced, I don't have to replace the pipes in the bathroom?

Absolutely key is a plumbing professional who is experienced with gravity systems and knows what they are doing. That is essential to obtaining a system that will be designed and work properly with your future requirements in mind.

You will not get 0.5bar from the Hot and cold supplies if they are gravity fed and the Cold Water cistern(CWSC) is say a meter above the bathroom ceiling. Typically showers designed to work with low pressure systems have a min requirement of 0.1bar and are typically manual showers, not thermo mixers

To obtain a 0.5bar working head of pressure the CWSC would need to be at least 5m above the highest outlet on the shower, usually the shower head. The alternative would be to pump both hot and cold either by a separate dual pump, a power shower or a digital pumped. Avoid trying to mix mains cold with gravity hot as it invariably causes problems with the supplies being unbalanced.