Can I Use Hot Water From The Tap (in Uk)?

[jonnyc88]

I would like some feedback from UK members.
During winter do you use water from the hot water tap for water changes?
I have a combi boiler.

 

[Essjay]

It is OK to use hot water from a combi boiler since the hot water is made on demand from mains cold water.

Hot tap water should not be used when hot water is stored in a cylinder which is topped up from a cold water tank in the attic. There are systems where the cylinder is topped up from mains water and those are OK.

The reason is simply that the header tank in the attic is rarely secure against things getting into it. Dead rats, pigeons etc have been found in them. We used to get wasps nests in the attic so we had a man come to remove them and he sprayed insecticide in the attic. We often found dead wasps in the header tank afterwards.
With this system, you should not use hot water for cooking etc, and if the bathroom cold water comes from this header tank you shouldn't drink it or even clean your teeth in it.

 

[AilyNC]

I've a combi boiler but we also have an attic tank to increase pressure. So it's only a good idea if your hot tap comes from the mains supply & not from a reserve in the attic

 

[Essjay]

If any of the hot water comes from the header tank I wouldn't use it.

I use boiling water from a kettle to warm the new water. I make up 7.6 litres water in a bucket (the dechlorinator dose rate is 1 drop per 3.8 litres) and in winter I mix in 1.5 litres boiling water while in summer I use between 1 and 1.25 litres.

 

[jonnyc88]

Thanks all. My home does have a tank in the closet but as far as I'm aware that's for heating the water from the solar panels.

Anyway I think I'll just use boiling water instead just to be safe. When I was doing water changes initially I was mixing it with some of the water from the hot water tap but have since stopped.

 

[Essjay]

It is only when there is a tank in the attic which fills the hot water tank that hot tap water should not be used. If the tank is filled directly from the water mains, it is safe to use hot tap water.

Whenever we moved house I always got someone to run the cold bathroom tap while I sat in the attic to see if that water came from the attic tank. You could always do the same with your hot water if you are unsure if it comes from the attic tank.

 

[ClownLurch]

I’m a carpenter and when doing loft conversions and other roof area type work I’ve seen some awful stuff in header tanks. Wouldn’t have one if possible.
There were three old ones in our loft when we moved here. I ended up making a bigger loft hatch to get rid of em but those galvanised ones are surprisingly heavy. Lowering it down on a rope it nearly took me with it.
Ill be buying a python or equivalent now I’ve learnt combi water and pre dosing left in water during a change is ok. The bucket and jug thing grows old very quickly.