does it turn fully and stop either way .
if your feeling water passing through the return pipe then this doesnt indicate an air lock
Airlock in HW Cylinder Gravity Fed Open Vented HW/CH system
- Thread starter bauk
- Start date
does it turn fully and stop either way .
if your feeling water passing through the return pipe then this doesnt indicate an air lock
Sponsored Links
I feel the vibrations of the pump and when I turned on the hot water I could feel the return pipe get warmer from the cylinder water that was already warm from the morning. At this point the feed to the cylinder was still cold as the boiler had just started up.
I also noticed when the heating and water were on the temperature of the top part of the feed pipe going to the cylinder slight cooled as the boiler was working for both heating.
I also noticed when the heating and water were on the temperature of the top part of the feed pipe going to the cylinder slight cooled as the boiler was working for both heating.
Sponsored Links
No he didnt , why would you drain anything to change an actuator ?
Maybe I miss spoke in my terminology, but he had to change the mechanised valve in the pipe work because the previous plumber broke the spindle and shoved the broken spindle into the back of the motorise box in front and left it like that. This plumber had to then not only change the valve mechanism installed in the pipe but also the motorised box as there was a part stuck in it. The first plumber said everything was working, but turned on the immersion so mask the broken zone valve.
i was so mad when discover what he did. I have no issue that the spindle broke as I’m sure it can happen to anyone, but to have no integrity and be deceitful is unforgivable. Unfortunately my experience hasn’t been good this time around with plumbers, hence my post on this forum to gain some knowledge and understand so I can either rectify the situation myself as long as it is safe or steer a plumber in the right direction.
Have you tried opening the HW motorised valve, closing the CH valve, and running the pump? That would put pumped flow through the cylinder and might clear any airlock.
Also the way your kit is piped, with some wiring mods it could be converted to a fully-pumped S-plan system, giving improved HW performance.
I wouldn't be too sure the pump isn't at fault. Some years ago I had a slight kettling noise, but had no reason to suspect the pump. Then the pump started to vibrate badly so I changed it. That cured the noise, and was OK at speed 1, vs speed 3 on the old one. When I looked into the old pump the impeller was full of sludge. Consists of 2 stainless steel discs 2mm apart and the gap was solid with sludge. If yours is like that, you could give it a good clean, no need to buy a new pump. And no need to disturb the pipework, just remove the motor/impeller, 4 Allen bolts usually.
Last edited:
I can't see that. Provided the manual valve is open, even when both the MVs are closed the system is open to the atmosphere, via the cylinder coil admittedly. Though the boiler would only be firing if the CH MV is open. As far as we know it's been OK so far.
Last edited:
Under normal operation when turning on the H/W the central heating zone valve closes and the h/w zone valve opens. The pump on the return leg to the boiler continues to run as I can feel a slight vibration on the return pipe.
Thanks for the advice regarding the pump. I’ll certainly have this looked at as a potential fix.
I can see your point actually. I suppose technical there is a route to the vent through the return pipe and then through the cylinder. It would be against the flow, but if the h/w isn’t on then I suppose the circulation of h/w would not be flowing.
After studying the initial diagram in great detail, the cold feed connection to the expansion tank would indeed give you some protection from an explosion if the boiler fired up with the h/w demand mv closed (satisfied) and the c/h mv still open (calling) for heat.
Still not a good state of affairs for any system to be in though.
Still not a good state of affairs for any system to be in though.
That suggests it's already working as an S-plan, with pumped flow through the HW cylinder
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
Sponsored Links
