Heating Water For Water Changes

Hi, I've been wondering about something and if it was a good idea.

At the moment when I do water changes I heat 3 big pans up on the hob but this takes quite a while to heat enough to do my two tanks. My question is that with a combi boiler would I be ok to take the water directly out the hot tap, mix it with cold to get the desired temperature then add my de-chlorinator before adding it to the tank?

I thought it would be ok as the water is only heated in the boiler as it's needed and is never standing in a hot tank.

Thanks

Thanks for the reply Richard.

I'm in Moray in Northern Scotland so the water is very cold when it comes out the tap at the moment. The temp of the water I'm adding is often a few degrees cooler but didn't want to shock my fish too much.

Generally speaking, hot water from a combi boiler is safe though I have heard of someone who had all their piping replaced at the same time as getting a brand new boiler and the copper from the pipes killed their shrimps.

It is when the hot water sits in a tank that you need to be careful. Not because of copper from the tank but because of the header tank. This is the open topped tank in the attic which fills the hot water tank when you run hot water. There have been all sorts of nasties found in header tanks including dead rats and pigeons. We have had 2 wasps nests in the attic which were removed and the chap also sprayed insecticide on the site. When we needed to change the washer in the header tank tap, we found a lot of dead wasps in the water. Were they covered with insecticide? I would rather not risk it, so I boil a kettle.
I either put a full kettle of boiling water (1.5 litres) into my 7.5 litre bucket and alternate between the warm water and a bucket of just cold; or I use 0.75 litres boiling water in every 7.5 litre bucketful, which of course amounts to the same thing.

i fill a 25 liter barrel i bought of ebay the night before i do my water change drop in a small heater and leave it over night then next day i add it to my tank saves waiting for the kettle

I tend to fill a bucket with cold water, at the water treatment and leave it sit by a radiator for 24 hours. Whilst I have no scientific basis for this, I feel it gives the water time to settle and the treatment time to take care of the nasties. By putting it by the radiator its usually a fair bit warmer than water from the cold tap. It's never as warm as the tank, but like Richard said, my fish seem to enjoy swimming in the cooler water.