Vaillant Combi Ecomax 824 problem

[Basecoat]

Hi All

Last two days my boiler was slowly loosing pressure. Reading posts on this forum this morning I checked pressure in expansion vessel and any leaks around boiler. I found relief valve was weeping. I followed forum instructions. The boiler pressure is now holding but strange occurance this afternoon.

The boiler switched itself on delivering heat when both the timer and room thermostat were off. My time settings are boiler on at 4-8am and 3.30-10pm. Before and after these times the system is off.

I would be grateful to all for helping me to locate and solve this problem. Thanks in advance.

 

[gas4you]

What timer/programmer do you have? Is it a Vaillant plug in on the front? if so it could be simply the warmstart/aqua comfort firing up to keep the DHW heat exchanger warm!

 

[Basecoat]

What timer/programmer do you have? Is it a Vaillant plug in on the front? if so it could be simply the warmstart/aqua comfort firing up to keep the DHW heat exchanger warm!

Hi "gas4you"

Silly of me forgetting relevant details to help diagnose the problem. The timer is a single channel fitted some distance away from the boiler. I have noticed boiler firing from time to time as you say but this afternoon it was very strange for boiler to fire up delivering heat. The heat was noticeable upstairs more so. Could it be the boiler engineer got wiring mixed up. I am saying this because he was confused when rewiring.

All other functions are working ok.

 

[gas4you]

Always possible that wiring is incorrect, but if this is the case why has it only now started, or do you think you have not noticed it before. Possible that the external control connector on the wiring block has been left in so therefore making boiler ignore timer etc.

I'm wondering if flow switch is sticking/stuck and diverter valve stuck so boiler firing to keep DHW ex warm and warm water rising through gravity to upstairs rads. Does your hot water perform nice and hot? does the flow pipe get hot when hot taps turned on?

If timer being over ridden by faulty wiring I would have thought downstairs rads would get warm as well

 

[Basecoat]

Always possible that wiring is incorrect, but if this is the case why has it only now started, or do you think you have not noticed it before. Possible that the external control connector on the wiring block has been left in so therefore making boiler ignore timer etc.

I'm wondering if flow switch is sticking/stuck and diverter valve stuck so boiler firing to keep DHW ex warm and warm water rising through gravity to upstairs rads. Does your hot water perform nice and hot? does the flow pipe get hot when hot taps turned on?

If timer being over ridden by faulty wiring I would have thought downstairs rads would get warm as well

Hi "gas4you"

Like you say I have not noticed until this afternoon. The boiler was rewired last thursday. All of my family was pleased to have our boiler up and running after being without it for over 8 months.

We were managing with electrics both hot water and heating. Some rooms were difficult to heat. Hot water was our biggest problem. Immersion cylinder is not big enough.

Hot water performs well with plenty of hot water. I have had the guy out checking the wiring. He had crossed one of the wire. He has tested the system through timer and room thermostat the boiler is working. I will check it in morning and report back if the problem has been solved. Thanks.

 

[Basecoat]

Always possible that wiring is incorrect, but if this is the case why has it only now started, or do you think you have not noticed it before. Possible that the external control connector on the wiring block has been left in so therefore making boiler ignore timer etc.

I'm wondering if flow switch is sticking/stuck and diverter valve stuck so boiler firing to keep DHW ex warm and warm water rising through gravity to upstairs rads. Does your hot water perform nice and hot? does the flow pipe get hot when hot taps turned on?

If timer being over ridden by faulty wiring I would have thought downstairs rads would get warm as well

Hi "gas4you"

Like you say I have not noticed until this afternoon. The boiler was rewired last thursday. All of my family was pleased to have our boiler up and running after being without it for over 8 months.

We were managing with electrics both hot water and heating. Some rooms were difficult to heat. Hot water was our biggest problem. Immersion cylinder is not big enough.

Hot water performs well with plenty of hot water. I have had the guy out checking the wiring. He had crossed one of the wire. He has tested the system through timer and room thermostat the boiler is working. I will check it in morning and report back if the problem has been solved. Thanks.

Hi "gas4you"

Reporting that all is well again. The engineer got 2 wires mixed. The boiler is holding its pressure and works as it should do. Thanks for responding to my thread. Your response helped me to think positive.