no hot water even though cylinder is hot

[southcoastboile]

Went to this one today, hot water only luke warm at best from hot taps.

Indirect cylinder, gravity fed system. Cylinder is scolding hot.

My thoughts were either bath shower mixer cold feeding back down hot or o/v pipe somehow fallen into the tank and sucking in cold water through o/v.

Any other ideas? this was my 13th job so going back tomorrow.

 

[gassafe]

At all outlets or just the bath shower mixer?

 

[gassafe]

Hot water outlet scaled up solid maybe if the tank is scalding off a gravity circuit

 

[southcoastboile]

All outlets, that's a thought thanks gassafe, don't think it would be that though as the flow is good from the hot outlets, just not very hot.

 

[Best]

I would look at the cylinder vent down into cwt & perhaps also a partly blocked cold feed pipe to the cylinder.
Cold mixing to hot from a mixer is unlikely if all gravity. Mains mixing likely but the cwt would overflow eventually.
On a Willis external heater connected wrongly to cyl feed, it is possible to have hot water stored but cold water coming out of hot tap.

 

[southcoastboile]

Thanks ^

 

[southcoastboile]

Sussed this one, open vent pipe had fallen in tank and was sucking in cold water.

 

[gassafe]

The cylinder had made itself a blending valve then lol... Nice to have an easy fix! I will remember this one...