Hot water from cold tap!!!

BeeDI

Seem to have developed a weird issue recently.
When I turn on the cold tap in the bathroom, I get a run of luke warm water for say the first 20 to 30 seconds, before it reverts to cold feed.

What on earth could cause that? Only recent change in plumbing is we installed a stove with back boiler, where just had a non boiler open fire before. Main heating is from oil fired boiler.

Confused???

GreeBo

Does it only happen if he hot tap has been running or can you just walk up and turn on the cold tap and get warm water?

I'd guess that one of your new pipes is resting against one of the existing bathroom cold pipes, if it was an overflow issue the cold tank in the attic would be slightly warmer but the tap water would be a consistent temp and you would hear boiling etc.

CJhaughey

I have the same issue, the pipes from the DHW tank run near the cold water and copper is an excellent conductor, when I turn the tap the first 1/2 litre is cool, the next 1/2 is warm and the then it turns cold as the outside water runs through the pipe.

sullzz

check that your header tank is not pitching when heating is on

JohnnieK

I have the same problem. The hot water pipe is touching of the cold pipe in the hot press. I put some pipe insulation on it and it sorted the problem.