Combi Boiler question

[Diyisfun]

With a combi boiler supplying hot water to a tap/shower mixer, does the cold supply have to be mains fed, or can it be supplied via a tank.
Also
If you are supplying the cold from the mains, would you normal supply the water to toilets from the mains or a tank.

Would you also restrict the mains cold supplyt to the tap to stop it spraying everywhere.

 

[Whitespirit66]

With shower mixers, its usually better to have balanced H and C supplies, eg. either both mains, both pumped or both gravity. However, this isn't set in stone, and varies between different makes and models of mixers. Check instructions for more info. If the hot supply to shower was mains/combi, and the cold was tank/gravity, the mains hot could force the weaker cold flow back up its pipe to the tank.

Normally if a combi is installed in a house that had gravity hot and cold supplies, the cold is converted to mains fed as well as the hot from combi.

If the flow of water to taps proves a problem, you could turn the stop tap down a little.

 

[bengasman]

Why do you ask?

 

[Diyisfun]

Why do you ask?

Because I was told you had to have cold water at mains pressure if you had a combi, I said thats silly as should you have the water turned off at the mains you have no backup supply, ie for toilets.
So the answer I got agreed with my thinking...
Why did you ask, why I asked..

 

[Agile]

If everything is in good condition then its often better to keep a loft tank to feed WCs and just feed the shower cold with mains cold.

Then flushing WCs does not upset the person taking the shower.

Tony

 

[bengasman]

Why did you ask, why I asked..

In other words: what is the problem?

 

[Diyisfun]

Why did you ask, why I asked..

In other words: what is the problem?

No problem, just one of those things that I was interested in.