Is this a frost stat?

[Observer]

The pic below shows a stat of some sort fitted to the flow pipe from my boiler. The electrical flex goes to a junction box where boiler controls enter/exit from boilers and various room or hot water stats. The system was fitted 20+ years ago. I've never been sure what the purposes of this stat is but guy who just did boiler service says it is a frost stat because the boiler and pipework is installed in a garage. However, does that make sense given the temperature setting of 80 deg. (I can't guarantee this is how it was originally set)?

Any comments welcome.

 

[cross thread]

Normally link that to a wall mounted frost stat, the frost stat turns it on and the pipe stat knocks it off so the house doesn’t overheat,set it to 30 if it’s wire up as stated

 

[Observer]

Normally link that to a wall mounted frost stat, the frost stat turns it on and the pipe stat knocks it off so the house doesn’t overheat,set it to 30 if it’s wire up as stated

Thanks. Actually the boiler service guy just called me and said it's something to with the distance between the boiler and the hot water cylinder (a Megaflow), which is some distance away - boiler is in basement garage and cylinder is in first floor cupboard. Could it be something to do with making sure that the water temperature in the coil at the cylinder is always high enough to raise the DHW supply to the setting on the cylinder stat? Does that make sense?

 

[Madrab]

guy who just did boiler service says it is a frost stat because the boiler and pipework is installed in a garage

Get someone else to service you boiler if he thinks that's a frost stat.

Looks like a cylinder stat that being used as an overheat stat for some reason, what boiler do you have?

A thermostat like that isn't there to override the other safety temperature controls to ensure the water in the pipe reaches the temp on its dial, or at least it shouldn't be. A stat like that is there to ensure that once something reaches the temperature on the dial it then shuts down so it doesn't overheat ... more a safety cut off switch, if you see what I mean.

So no it shouldn't be there to ensure the water gets to the cylinder hot enough. The boiler output temp would be set to ensure that happens.

 

[ianmcd]

It is not a frost stat it is a pipe stat, normally used in conjunction with a frost stat but that setting is far too high, as you have said,might have been fitted as some kind of un-needed Heath Robinson attempt to control HW temp