JeffR

Aha.. I'll try that. Will have to be tomorrows job now. Part of the fire sprinkler system and totally separate from everything else..

'Temp', I just had a look at the pump (Grundfos UPM3 Auto) and downloaded the manual. I'm not going there regarding manual control!! It's some kind of load controlled device and the settings are already different to the factory pre sets, so I think its safer to stay away from that. Here's a few shots of the system: Pic 1: Manifold next to boiler. Boiler is in loft. One loop (without actuator) just goes from supply to return, so I guess this is doing nothing. The other loop I think, is the upstairs bathroom. Pic 2: On both supply and return manifolds, there is this 'pot'. Has a Schrader valve on top and what looks to be a hose coupling underneath. Pic 3: The manifold in the basement (below the room that won't heat). How do I go about bleeding or am I in expert territory now??? (I am a mechanical engineer, reasonably confident, but not reckless!!) AdamSee: I don't hear any gurglings..

Hi All, I so appreciate everyone's input on this. I'm no plumbing expert, but like to at least understand the problem before handing it over to a grown up.... To address PeterW's comment re actuator: I removed both actuators today and let run for 7 hours. Only reached 18.5 deg C. Can just about feel some warmth underfoot, but pretty dismal. Hallway next to this room is sitting toasty at 21C. So, I'm really hoping its an air issue. If indeed it is, would the flow levels still indicate full flow? I'll try and take more photos tomorrow, but my system comprises: Boiler at the top of the house. There's a manifold next to boiler. Will investigate what's attached to it tomorrow. All upstairs rooms on radiators, except for 1st floor bathroom which is wet underfloor. (All work fine) At ground level, i have kitchen, hallway and living room (which is the one playing up). All underfloor. There's a family room on a level halfway between ground and basement. (its a weird split level house). In the basement (where main manifold is), there's a bedroom, a bathroom and an office. I take on board the comments about manifold should be below loops, but I have at least three other loops above the manifold that seem to be operating fine. I'm really hoping its just just this one that's got air. It's only been on 2 or 3 times in 2 years. JFDIY: Before I look into a hose pipe bleed, how do i manually set pump to maximum?? Thanks everyone..

Testing again this morning with actuators removed (meaning valves open). Let's see!

Morning All, Thanks the feedback so far. JFDIY: Manifold is in the basement. Room not heating up is in the room directly above. I have bigger rooms further away, so don't think it's that. Pretty sure loops aren't mixed (hot/hot and cold cold) as like Temp says, there is flow and both sets of pipes get hot. Update: I set everything to 22.5 degC overnight. Some circuits (kitchen, dining room) I'm familiar with as they come on everyday. The others are more often set to off, so I'm less familiar and the zones could be mixed without me realising. The result: everything pretty much reached temperature APART from the problem room which got to 18.0 deg C. This room was previously 14.5 before I started al these tests. The problem room is directly above the basement room and I checked the basement ceiling to see if that was warm (lack of insulation as Temp suggested), but felt nothing. I'm pretty sure that this room has worked OK in the past, although I've only had it on once or twice since being installed and it could have been when days were warmer? Could it be that the loop needs bleeding? But that said, it does show flow and both supply and return pipes are hot..

Hi Temp, Thanks for the feedback. Lack of insulation can't be ignored as the builder who installed was hopeless (and has now gone bust). That said, I can recall that when it was set up, it did work at least once or twice. It's freezing here tonight, so before I go down the route of turning everything off, I'm going to turn everything on full blast and not timed. If the floor then heats up, I'll at least know its not a fault and can then start pinning down which zone is which. Thanks. Jeff

This is driving me insane.. I have a wet underfloor heating system, with Honeywell Evohome zoning. Most zones work fine and I believe all zones are labelled correctly. I have one room where the heating is hardly ever used (think I've had it on twice in 2 years), but wanted it on over Christmas. Despite the controller working, the room does not show any signs of heating (can’t feel anything underfoot). This is even after leaving heating on for days. There are two circuits in this room (dunno why, it’s not the biggest room by far), and both show full flow when on. Grabbing the pipes, flows and returns are hot in both loops which to me indicates nothing is blocked, so why won't it heat up?