CH boiler in loft - frost protection ?

[Wildy58]

I have recently had a Ravenheat 85T condensing boiler fitted in loft, with a hard wired (not the wireless version) Salus RT500 programmable thermostat in the hallway. This thermo operates between 5 and 35deg C and uses 'volt free switching' as advised by Ravenheat.

My questions are simple ones (everyone says that !) :

- If the loft temp falls below 0 and the house thermostat registers above 5 deg C, will the water in the boiler itself freeze ?

- If so is there a frost thermostat I can buy (needs to be volt free switching) that I can use in the loft to protect just the water in the boiler ?

All the pipes in the loft are properly lagged but there is no heating in loft of any form so boiler is my only concern as it will get very cold in there.

Any advice would be greatly appreciated.

 

[grahamderek]

check the boiler specs.
nearly all modern boilers have built in frost protection
your installer should have gone through this with you

 

[Wildy58]

Thanks, I checked the book but not 100% clear to me and didn't think to discuss with Corgi fitter at the time.

Manual says this >
2.3.4 The boiler water temperature is automatically controlled by a built in thermostat.
2.3.5 Interior space temperature is set by the room thermostat to be installed in the heating system. The boiler already carries connection terminals for this thermostat, as well as for a timeclock. The burner continues to operate until it is stopped by the timer or one of the thermostats.
2.3.6 When the internal C.H. temperature sensor intervenes the main burner shuts down. The fan stops but the pump continues to operate.
2.3.7 When the room thermostats intervene the main burner shuts down. The fan stops and the pump turns off.

I was not sure whether the 'built in' thermo would still kick in as there is a room thermo. Can boilers take instructions from either thermostat to fire up for frost protection ?

 

[grahamderek]

I cant find my way round Ravenheat's rubbish web site.
The simplest way is probably to ring their technical help line

 

[Wildy58]

Believe me I have tried that already !

Hence why I am here - asking people who have more experience / higher IQ'a . . .

 

[gas4you]

Just checked the service/installation book and in the front it states in has frost protection.

 

[Wildy58]

Thanks for advices.

In laymans terms does that mean the boiler has it's own thermostat that senses the temp inside the boiler (in freezing cold loft) and then overrides any other room thermostat (down in main house) and fires the burner ?

 

[gas4you]

Yes, but still make sure you have all your pipe work insulated in the loft.

 

[Wildy58]

Dave, thanks for your advice.

All pipes are lagged to death - there is no way they'll freeze . . !

 

[JoeMar]

http://www.ravenheat.co.uk/pdf/CSI85/CS185ScreenV3.1pdf.pdf

Read Page 2 - Major Components

...built in Frost Protection.

 

[Wildy58]

joemar,

Thanks.

I had already read through the book when it came with the boiler.

The one question that I was trying to answer was whether I need any extra frost thermo in the loft to protect the boiler or can it protect itself ( if loft ever got near to sub-zero temp ) via an internal thermo, and also bearing in mind the room thermo / programmer is 30ft away and downstairs.

As all pipes in loft are well lagged and beneath the boiler is 10" of loft insulation it is gonna get cold in winter.

In the literature there are numerous refs to an 'Overheat Thermostat' but none at all to a 'Frost Protection Thermostat'.

From the earler replies I take it the boiler has it's own internal thermo which will sense the loft temp and fire up if it falls below 5degc. So I don't need to add an extra frost thermo in the loft.

Thanks everyone !

 

[JoeMar]

unfortunately the manual doesnt go into much detail about the frost protection for your boiler.

On my Vaillant you can set different parameters for frost protection.

 

[tonybhoy]

I always fit an external frost stat for installations in unheated areas. The boiler frost stat only protects the boiler ,once the boiler gets to the set temp the stat switches the boiler off however the pipes in the immediate area of the boiler are not protected regardless of how well insulated they are.

An external frost stat cost about a tenner and any decent spark will fit it at the same time as the boiler electrics for nothing,well mine does.

 

[gas4you]

I always fit an external frost stat for installations in unheated areas. The boiler frost stat only protects the boiler ,once the boiler gets to the set temp the stat switches the boiler off however the pipes in the immediate area of the boiler are not protected regardless of how well insulated they are.

An external frost stat cost about a tenner and any decent spark will fit it at the same time as the boiler electrics for nothing,well mine does.

If you go this route don't forget you will need a pipe stat as well, wired in series, otherwise the boiler will be firing up all night

 

[tonybhoy]

I always fit an external frost stat for installations in unheated areas. The boiler frost stat only protects the boiler ,once the boiler gets to the set temp the stat switches the boiler off however the pipes in the immediate area of the boiler are not protected regardless of how well insulated they are.

An external frost stat cost about a tenner and any decent spark will fit it at the same time as the boiler electrics for nothing,well mine does.

If you go this route don't forget you will need a pipe stat as well, wired in series, otherwise the boiler will be firing up all night

Thanks for the advice however I'm not bothered about the price of fish!