Boiler Frost Protection

[Mattvw]

Hi Ian,
Why is that? Both 2 way valves are closed as the heating and hot water aren’t calling, so the prv allows the water to circulate back to the boiler as I understand it/was told by installer?

 

[Mattvw]

Hi Ian,
Why is that? Both 2 way valves are closed as the heating and hot water aren’t calling, so the prv allows the water to circulate back to the boiler as I understand it/was told by installer?

 

[snb]

my guess is that the frost stat has not had the front dial put on in the right place. might say 5 degrees but is probably coming on at a higher temp. check pipestat but reduce to 15 degrees.

it also need the wiring altering. the froststat and pipestat arrangement should be altered so that it opens the heating 2 port valve. this way when they do activate the pump sends water from the house at about 20 degrees and it turns off very quickly

 

[Mottie]

Hi Ian,
Why is that? Both 2 way valves are closed as the heating and hot water aren’t calling, so the prv allows the water to circulate back to the boiler as I understand it/was told by installer?

That’s the ABV isn’t it? Automatic Bypass Valve. PRV is a pressure relief valve that lets pressure off before things go bang!

 

[Terrywookfit]

What is the prv you say is whistling

If you mean the ABV.…...It does not need one as no overrun.

 

[Mattvw]

my guess is that the frost stat has not had the front dial put on in the right place. might say 5 degrees but is probably coming on at a higher temp. check pipestat but reduce to 15 degrees.

it also need the wiring altering. the froststat and pipestat arrangement should be altered so that it opens the heating 2 port valve. this way when they do activate the pump sends water from the house at about 20 degrees and it turns off very quickly

thanks for that. I’ll talk to the installer and suggest what you’ve said.

 

[Mattvw]

Sorry guys, I’m not a plumber, yes I guess I should be referring to it as abv rather than prv.

 

[Terrywookfit]

If the ABV is close to the boiler it will be heating a small volume of water which will rapidly cool

 

[Mattvw]

I don’t actually know where the bypass valve is from memory. I’ll have a look in the garage tomorrow as I assume that’s where it is.
I thought whilst the heating is clicking on and off on a cold night like tonight though, that the system should be warm enough to not have the frost stat kick in several times an hour?

 

[ianmcd]

Hi Ian,
Why is that? Both 2 way valves are closed as the heating and hot water aren’t calling, so the prv allows the water to circulate back to the boiler as I understand it/was told by installer?

you mean the automatic by pass,ABV, the PRV is the pressure releif valve it vents water to outside if there is a failure on the system, not the same thing

 

[Terrywookfit]

I don’t actually know where the bypass valve is from memory. I’ll have a look in the garage tomorrow as I assume that’s where it is.
I thought whilst the heating is clicking on and off on a cold night like tonight though, that the system should be warm enough to not have the frost stat kick in several times an hour?

Is the frost stat close to the boiler to sense the heat . It is quite possible to be 20° in the house and 3° in an unheated garage, The outdoor boilers have the stat in the control panel to sense the boilers heat.
I would also check the return pipe temp when heating is on if the pipe stat is operating 30 secs later.
It must be kept above 50° to prevent "Back end Rot"!!