Hot water tap takes 10 minutes to come on?

[frostyfpr]

Hi there, i really need help as i am absolutely baffled. We have a DUX hot water system, my problem is that only in the main shower the hot water tap has NO water coming out for around 10 mins, it will then kick in. but the basin sink tap next to the shower, the hot water works straight away.
All other hot taps in the house work as they should. I have replaced the washer on this tap. Cold water works fine straight away. I have googled everything. It is no water at all for about 10 mins, then it will start. If you turn off and straight back on again it takes a bit of time still to start up again, Anyone please had this problem before or can help with advice? Thanks

 

[Chuck]

Measure the flow rate coming from the problematic tap and one that is working okay. (Use a jug and a stopwatch.) Compare the litre / minute with the minimum specified in the owner's man. (IIRC, ca 2.5 litre/min is a typical lower limit for the heater to come on.)

Your unit may need servicing / adjusting by a suitably qualified heating engineer.

 

[frostyfpr]

Hi mate, thanks for the response. So should i wait the 10 minutea it takes for the water to come on, then measure? Its only that one tap that it waits 10 mins to come on. cheers

 

[Chuck]

Hi mate, thanks for the response. So should i wait the 10 minutea it takes for the water to come on, then measure? Its only that one tap that it waits 10 mins to come on. cheers

No need to wait.