Gloworm ultracom 30cxi shower and taps run cold after 1 min

[pikeyhorshoe]

Ive got a Gloworm ultracom 30cxi, its been a right pain since it was installed 7 years ago, its had 2 heat exchangers since new.

Recently the shower has started running cold after about 1 minute, and the upstairs bath the same, the upstairs sink hot taps fluctuate warm/cold, never getting hot at all. Sometimes they stay warm for longer but always run cold after a while.

The kitchen hot tap runs hot and stays hot, this is the closest tap to the boiler.

What do you think could be the problem? Do I need a new heat exchanger again ? Since the last heat exchanger 2 years ago I had a limescale device fitted around the supply pipe, not sure how it works, it just clamps on. Hope this would prevent the heat exchanger clogging up again.

thanks

 

[cross thread]

poss plate heat ex of water flow sensor

 

[St0rmer66]

Sounds like plate heat exchanger again.

 

[ScottishGasMan]

The fact that the closest tap runs hot with no problems would be much more suggestive of a passing mixer valve (bar shower mixer?) going faulty.

If you run the hot tap at the bath and its going cold/luke warm, then isolate the cold inlet under the boiler so as to stop any flow though the boiler, the water should stop running completly at the hot tap, if there is still some cold flow at the tap then you have a mixer valve allowing cold into the hot pipes and mixing down the hot water.

Def worth a check first based on the symptoms.

 

[St0rmer66]

Missed the kitchen tap part . Agree with SGM.