You don't reckon they've set that pipe stat up so it switches the pump OFF once the pipe reaches a certain temperature do you? As a very crude way of controlling the UFH? Perhaps UFH pump is always on when central heating is on, with the pipe stat turning it off at a certain temperature?
On an aside, the install is a bit naff with pump shaft at 45 degrees from horizontal (and electrical enclosure on the underside of it) etc, but that won't be the problem, unless it's knackered the pump bearings (unlikely).
Have you tried turning that thermostat both up and down (it'll click)? Also, the speed selector on the pump (on the electrical enclosure on the underside) can be clicked up and down from speeds 1 to 3 or I to III and you'll certainly hear/feel it if it's running on 3 or III.
Make a note of all existing settings before you fiddle with switches etc.
Underfloor heating can quite easily airlock - you normally have to blast mains water through it when you first install it, perhaps air got pushed in during the works? Though an airlock won't generally stop a pump turning.
As an aside, if the pump hasn't run all summer, it may have seized... Look upo how to free off a jammed central heating pump - various pictures and videos online.
On an aside, the install is a bit naff with pump shaft at 45 degrees from horizontal (and electrical enclosure on the underside of it) etc, but that won't be the problem, unless it's knackered the pump bearings (unlikely).
Have you tried turning that thermostat both up and down (it'll click)? Also, the speed selector on the pump (on the electrical enclosure on the underside) can be clicked up and down from speeds 1 to 3 or I to III and you'll certainly hear/feel it if it's running on 3 or III.
Make a note of all existing settings before you fiddle with switches etc.
Underfloor heating can quite easily airlock - you normally have to blast mains water through it when you first install it, perhaps air got pushed in during the works? Though an airlock won't generally stop a pump turning.
As an aside, if the pump hasn't run all summer, it may have seized... Look upo how to free off a jammed central heating pump - various pictures and videos online.
