Vaillant boiler start up question……..

[SteveL63]

Hi, I have a Vaillant Ecotec Plus 637 condensing boiler and its working okay, serviced about a year ago. Just something I noticed the other day, when the central heating program or hot water program (it heats an unvented cylinder twice a day) come on there is a 3 minute or so delay for the hot water to leave it through the hot water out pipe. The boiler kicks on, the flame lights up (the flame symbol is there) and all the symbols on the front are there like pump on, egg timer one etc but although it’s doing that no hot water leaves it for about 3 minutes. After that the boiler cuts off for a second or two, immediately fires up again and the hot water comes straight out, the exit pipe is immediately very hot, and everything works fine after that. There are no fault codes or anything but is this delay normal or is it something that needs an engineer to come out and look at as to my untrained thinking if the boiler is heating water for 3 minutes from cold where is it going?
Thanks,
Steve.

 

[Last Plumber]

It will be circulating but on low fire so the water is leaving but not picking up much heat. Can be a delay sometimes if the flow and return temps are too far apart.
I wouldn't worry about it if it doesn't do it all the time but it is worth mentioning to the engineer next time it is serviced so they can check the set up of the boiler & system for you. If it bothers you or it has changed recently, ask someone to check it over sooner.

Any 'S' codes displayed?

 

[SteveL63]

It will be circulating but on low fire so the water is leaving but not picking up much heat. Can be a delay sometimes if the flow and return temps are too far apart.
I wouldn't worry about it if it doesn't do it all the time but it is worth mentioning to the engineer next time it is serviced so they can check the set up of the boiler & system for you. If it bothers you or it has changed recently, ask someone to check it over sooner.

Any 'S' codes displayed?

Hi, thanks for the reply. No, no codes at all, the display is just showing the normal symbols like burner on, pump running etc and it works 100% once it starts getting the hot water out. So I’ll just live with it until the next service, thanks for putting my mind at rest about it.

 

[Scott_D]

Sounds normal.
Low fire for around 5 minutes then ramps up.
Is it a large heating system to require 37kw? Might need range rating to suit.

 

[SteveL63]

Sounds normal.
Low fire for around 5 minutes then ramps up.
Is it a large heating system to require 37kw? Might need range rating to suit.

Hi, it’s a big old house, 6 bedrooms over 3 floors so I assume that’s why they picked a powerful boiler when it was installed (before we purchased the house). Thanks for the advice, I’ll just leave it to get on with it then!