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Andrew Smith
Andrew Smith, HVAC Technician
Category: HVAC
Satisfied Customers: 3629
Experience:  Heating and Controls engineer
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Please can you help? I had to turn the water mains off

Customer Question

Hello, please can you help? I had to turn the water mains off earlier & when I turned it back on there was no hot water (boiler is a vaillant eco tec pro24). Thought it must be due to the boiler water pressure so I refilled it and boiler water pressure is back up to normal, but I'm still getting error code f28 / f29 when I try to reboot it! I don't know what to do!
Submitted: 1 year ago.
Category: HVAC
Expert:  Andrew Smith replied 1 year ago.
Can you confirm the fan is running and trying to light?
Customer: replied 1 year ago.
Yes it's making lots of whirring noises but after a minute or two gives up and shows the error code again!
Expert:  Andrew Smith replied 1 year ago.
With your ear against the case can you hear the ticking as it is trying to light?
Customer: replied 1 year ago.
Not really - a few clicks right at the start but if you mean something like a stove lighter click throughout the process then no, I can't.
Expert:  Andrew Smith replied 1 year ago.
It sounds like it does not know the fan is running.You need to know if it is running (pressure blowing from the flue)
Customer: replied 1 year ago.
How do I test this? Do you mean the pipe on the side of the house that steam comes out of when the hot water is on?
Expert:  Andrew Smith replied 1 year ago.
Yes, if the fan is running then you will feel pressure against your hand from the centre.
Customer: replied 1 year ago.
Ok I have just climbed up there and can't feel anything.. Should the fan be on all the time or just while it is trying to do the reset process? Or just while the water is running?
Expert:  Andrew Smith replied 1 year ago.
The fan should be on whenever the boiler is running for hot water or heating
Customer: replied 1 year ago.
Ah ok have tried it with the tap running and yes, there is air blasting out of the pipe
Expert:  Andrew Smith replied 1 year ago.
Ok fan runs - next, does the boiler start ticking for ignition?
Customer: replied 1 year ago.
It clicks a couple of times at the start of the reset process. not sure if this is ignition or not? While it is showing the error code, turning on the tap doesn't seem to activate anything - no noises.
Expert:  Andrew Smith replied 1 year ago.
So the boiler does not try and fire on hot water at all?
Customer: replied 1 year ago.
Sometimes it tries to, just not while the red light is showing! I will have to sign off I'm afraid as its getting late and I'm up at 6 am for work - think I am going to have to resign myself to a cold shower this evening and call an engineer out tomorrow! Thanks for your help.
Expert:  Andrew Smith replied 1 year ago.
No problem, come back if you get stuck.