Unvented Cylinder No Hot Water

[Yogiblair]

Hi,

I have a Tribune Range HE, direct unvented cylinder with a gas boiler. Recently I had a very small leak (more of a weap) from the two port valve on the CH. I isolated the water supply, electricity and closed off the valves I could see directly effecting this circuit. I removed the actuator assembly cleaned up the two port valve, re-seated everything and all appeared ok. The leak has been fixed.

The next day after showers I ran out of hot water. One thing to note that I have been running this as an indirect system for over a year (immersion heater switched off) and always had sufficient levels of hot water.

The CH works fine. In investigating I noticed that i had zero pressure at the expansion tank. (when removing the two port valve there was a very small release of pressure) I opened the fill loop and now have 1.3bar at the expansion tank.

I can get hot water by turning on the immersion heater, however I have tried several tests now with the immersion heater off and after using the contents of the tank I get cold running through.

I have read that my problem may be with the motorized valve on the primary flow line. I have tried running this in manual but still get no hot water unless the immersion heater is on.

Any help greatly appreciated.

 

[Simon F]

so the lack of hot water has only occurred after the work you did yes?
apart from the possibility of a completely unrelated fault also occurring at the same time,
the issue more probably is that something has been changed, not put back properly.
Have another look, what did you change? has something been missed?
start simple - have the valves that were closed been opened?
did you change the wiring? is it wrong?

 

[Gray0689]

How do you know if the motorised valve you possibly fixed is working correctly

Open it manually and turn heating on see if you get hot water then

 

[Yogiblair]

Simon Thanks for the reply. Yes this has only happened since i removed the CH two port valve actuator and re-seated it. I closed two valves and opened them again at this time. I am thinking it is related to the small amount of pressure that escaped when I removed the CH two port valve and that there should have been another valve in this circuit closed? As I said I had zero pressure at the expansion tank but opening and closing the fill loop then gave me 1.3bar.

 

[Yogiblair]

How do you know if the motorised valve you possibly fixed is working correctly

Open it manually and turn heating on see if you get hot water then

The motorized valve on the central heating doesn't have a manual option (only the valve on the primary flow line). it is working because it turns when the central heating kicks in

 

[Simon F]

How do you know if the motorised valve you possibly fixed is working correctly
Open it manually and turn heating on see if you get hot water then

The CH works fine.
I have read that my problem may be with the motorized valve on the primary flow line. I have tried running this in manual but still get no hot water unless the immersion heater is on.

what Gray is saying is turn the central heating on, the boiler is then working Yes?
(so the pressure you mentioned is not an issue.)
then manually open the small metal lever on the 2 port valve to the hot water cylinder,the lever has a position that it can be held in so that it remains open, if the hot water is then getting hot - you still have an issue with the 2 port valve.

 

[Yogiblair]

what Gray is saying is turn the central heating on, the boiler is then working Yes?
(so the pressure you mentioned is not an issue.)
then manually open the small metal lever on the 2 port valve to the hot water cylinder,the lever has a position that it can be held in so that it remains open, if the hot water is then getting hot - you still have an issue with the 2 port valve.

I have done this with the metal lever in the manual position and the central heating on. Left it for several hours with the immersion heater off (power switch off) and still no hot water.

 

[Simon F]

I will come back then to the first answer, that if the problem only happened AFTER you did the work on the two port valve something must be closed somewhere to be preventing any flow.
is the valve put back together properly?
might be time to call a plumber to resolve the problem, as ability through a keyboard has limitations.

 

[Yogiblair]

I will come back then to the first answer, that if the problem only happened AFTER you did the work on the two port valve something must be closed somewhere to be preventing any flow.
is the valve put back together properly?
might be time to call a plumber to resolve the problem, as ability through a keyboard has limitations.

I will check valves again, but as I said I only closed two and then opened two. the two port valve is such a simple piece that I do not believe it be possible to not put it back on correctly. Thanks for your suggestions.

I am thinking that I have been unlucky and my problem is un-related. Perhaps it didn't like it when I powered down the system to to work on it originally. I have read elsewhere about a microswitch in the flow line two port valve and if this is faulty then even though the valve is manually open then the heating will not kick in to heat the water (although i would have thought it would still heat when the central heating is on)

 

[Howsie]

Are you sure it's back on its spindle correctly?