Fully pumped system HW 2-way valve closes and pump stop

Joined
10 Apr 2016
Messages
85
Reaction score
5
Country
United Kingdom
Hi all,
My system is fully pumped with two 2-way valves, open vented, coil cylinder, Boiler Potterton 50e and thermostat potterton EP2002. Page 316 of this link shows my system functional layout:
https://www.pearsonschoolsandfecoll...FreesamplechapterPlumbing/Level2_PLUMB_SB.pdf

The system CH works fine, when I slide the thermostat switch the CH valve opens and the pump starts. The Boiler flame starts and water get hot.

The HW system does not work well, resulting in cold showers.
This is what happens step by step:
1. I switch on HW in manual mode in the thermostat EP2002 which is sited in the airing board.
2. The HW 2-way valve motor runs (typical gear noise) and valves open
3. Pump starts
4. Pipe connected to Cylinder coil start getting hot.
5. However after few second the pump stops and the valve goes to rest position and closes.

I have checked the cylinder thermostat and looks fine.

I think the root cause may be:
1. Some problem with Boiler thermostat stopping the pump
2. Some problem with air in the piping (unlikely)
3. Some problem with the 2-way valve switches
4. Problem with the Potterton thermostat/controller.

Any idea/suggestion?

Many thanks
 
Sponsored Links
Can I suggest you start by looking for voltages at various points that keeps the HW motorised valve open.
 
Can you manually open the HW motorised valve and see what happens then.
 
Sponsored Links
Can you manually open the HW motorised valve and see what happens then.

Most likely nothing.
Manual opening should not engage auxiliary switch, so no pump or boiler operation.
However, OP will get hot water if CH running.
 

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

 
Back
Top