Frost control on Valiant ecofit pure conv 418

[Havent a clue]

Hi, I had a Valiant ecofit pure conv 418 boiler installed by the gas board in August, since then the pump has been coming on at various time through the night, I got the installer out and was told its the frost thermostat (the boiler is in the garage) and when it comes on it wakes me up as the tank cupboard is next to the bedroom and I can hear it operating the diverter valve and a filter. Valiant website says the frost thermostat kicks in at 12 degrees and operates until it reaches 15 degrees, this can take up to 30 minutes, this seems a bit high to me and I was wondering if it should be set at a lower temp, any help would be appreciated as I need a good nights sleep. Thanks

 

[Harry Bloomfield]

Valiant website says the frost thermostat kicks in at 12 degrees and operates until it reaches 15 degrees, this can take up to 30 minutes, this seems a bit high to me and I was wondering if it should be set at a lower temp, any help would be appreciated as I need a good nights sleep. Thanks

I don't think the setting is adjustable, but here is the manual -

https://www.vaillant.co.uk/downloads/product-manuals/ecofit-pure-1/ope

 

[Havent a clue]

Thanks for the quick reply, I have read on the valiant website that frost protection kicks in when the temp falls below 15 degrees but that seems high to me when other manufacturers say 5 degrees, thanks again

 

[JonathanM]

I think this is the installation manual:

https://www.vaillant.co.uk/download...tion-and-maintenance-instructions-1943278.pdf

5.5.3 Frost protection The appliance has a built in frost protection device that protects the boiler from freezing. With the gas and electric supplies ON and irrespective of any room thermostat setting, the frost protection device will operate the pump when the temperature of the boiler water falls below 12 °C. A timer is used so that the temperature can be checked periodically. After 10 minutes the pump will be stopped if the temperature is higher than 10 °C or has already reached 35 °C. The burner will activate if the boiler temperature does not reach 10 °C after 30 minutes or at any time if the temperature drops to 5 °C. The burner will switch off when the temperature reaches 35 °C.

 

[JonathanM]

I have read on the valiant website that frost protection kicks in when the temp falls below 15 degrees but that seems high to me when other manufacturers say 5 degrees, thanks again

From the above: It looks like it's a two stage process. Pump comes on at 12 degrees, burner comes on at either 10 degrees or 5 degrees. Vaillants are often complicated!

 

[Harry Bloomfield]

Thanks for the quick reply, I have read on the valiant website that frost protection kicks in when the temp falls below 15 degrees but that seems high to me when other manufacturers say 5 degrees, thanks again

I have the same boiler, difference is mine is installed in my kitchen, in a wall unit. Both will be subject to atmospheric air temperature entering via the flue - yet I have never noticed mine fire up on frost protection. I wonder if the difference might be the cupboard and indoors helping to keep it above the frost setting?

Might it be worth your while boxing it in temporarily, even trying some insulation? Another approach might be to box it in and add a small heater below the boiler, even a lamp, switched on by a stat as the temperature falls.

 

[Havent a clue]

Thanks again, that makes sense and is exactly what is happening, at least knowing it is functioning as it should makes things better, Thank you

 

[Havent a clue]

Thanks Harry that's good advice

 

[CBW]

Thanks for the quick reply, I have read on the valiant website that frost protection kicks in when the temp falls below 15 degrees but that seems high to me when other manufacturers say 5 degrees, thanks again

Assuming the linked manual is correct, then it states 5 degrees? Are you sure it’s open vented as they don’t have diverter valves.

 

[Havent a clue]

Thanks for the reply, the diverter valve is in the cupboard with the hot water tank along with a particle filter we had fitted when we had the old boiler, I think I have narrowed it down to the pump coming on and activating the diverter and filter which I can hear humming as the cupboard is next to the bedroom.

 

[CBW]

Thanks for the reply, the diverter valve is in the cupboard with the hot water tank along with a particle filter we had fitted when we had the old boiler, I think I have narrowed it down to the pump coming on and activating the diverter and filter which I can hear humming as the cupboard is next to the bedroom.

I’m not confident that would happen. Pump and 2/3 port valve (diverter as you’re calling it) are only activated by another switch, so a demand from cylinder thermostat or room thermostat from the initial requested demand from programmer. You could have a failing microswitch.

 

[Havent a clue]

I have tried setting the heating and hot water controls to off before going to bed but it still happens?

 

[CBW]

I have tried setting the heating and hot water controls to off before going to bed but it still happens?

A faulty microswitch will still fire the boiler irrespective of whether programmer on or off

 

[Havent a clue]

That's good information, I think I will get the gas board back out and have a look at it, I really do appreciate your help