Potential Danger or not?

[bobbon2005]

I have an 1991 Glow-worm economy, which has been reliable and so far trustworthy (given it's age).

It does have one minor glitch, you cannot programme to soley heat hot water anymore, you have to have it on with the central heating. On warm days we just turn the thermostat down and thus get hot water without the rads being on too.

However, recently I've noticed that when you turn the cold water tap on for the bathroom hand basin, the water comes out cold for 5secs, hot/warm for 5secs, then back to cold.

I may be wrong in this but somewhere in the deepest corners of my brain I can recall a story about a tragedy occurring in a family involving some kind of explosion and boiling hot water going everywhere and the pre-warner being hot water coming through the cold tap.

Have googled to no avail. Any ideas of whether my problem is potentially very dangerous?

Would be grateful of any help.

Thanks

 

[Agile]

I think you are describing a combi.

It sounds as if the DHW demand switch has failed.

It is no more dangerous than any other boiler. That means its prettty safe!

Better to get the fault fixed though.

Tony

 

[blondini]

I've noticed that when you turn the cold water tap on for the bathroom hand basin, the water comes out cold for 5secs, hot/warm for 5secs, then back to cold.

If it goes back to cold and stays cold it suggests that there is a section of the cold feed being warmed by close proximity to a heating pipe.