Heatmiser UH1-W, UFH Actuator and Manifold Pump

frslam

Hey guys, have an issue. Noticed rooms are cooler than should be. Checked the Heatmiser UH1-W and although the lights are on for room circuits and pump, there are no actuators energised. These are Emmeti actuators which are closed normal state. There are 7 circuits on the ground floor, all run by wireless (not wifi) room stats. The wiring centre (UH1-W) is receiving the commands from the stats. The pump output is lit up but the pump is not running. Anyone know it the actuators have a micro witch or something which may be bust and not allowing the pump to run? That's all I can think of. The system has been running for some 12 or 13 years. Strange for the pump and all actuators to not work. The actuators might have all given up slowly over time, they are in the under stair cupboard where they're never seen. I've had to remove some heads just to open the circuits to get some warmth into the house. I'm struggling trying to find replacement actuators, there's no part number on them - there's a number '2' on the top of them just by the name 'Emmeti' and a label on the cable which says '46/12' besides the power, ip rating and 3.5w. I believe these are 'normally closed' heads. Any help would be gratefully appreciated

matelodave

Which pump isn;t working. Has your system got a pump on the boiler and one for the u/f heating. Is the boiler firing uo ok and does the boiler pump run (say for the upstairs radiators)

If the Heatmiser is calling for heat and the boiler fires but the manifold pump and actuators aren't operating then it seem like theres a common fault thats inhibiting power to the actuator and pump relays - is there fuse somewhere. 

Have the actuators got two or four wires. Two wire types are just actuators wheras four wire means they've got a microswitch but it seems unlikely that they've all packed up at the same time. So dont go changing them all. Its possible that one has failed and taken out a fuse (I had that happen on one of my manifolds)

 I'm guessing that all the actuators are pretty similar a PTC heater heats a wax pellet which pushes out the operating pin - mine are Polypipe so you dont really have to change them with your specific brand.

the manual for the UH!-W isn't everso helpful - download one form the interweb if you haven got one.

frslam

matelodave said:

Which pump isn;t working. Has your system got a pump on the boiler and one for the u/f heating. Is the boiler firing uo ok and does the boiler pump run (say for the upstairs radiators)

If the Heatmiser is calling for heat and the boiler fires but the manifold pump and actuators aren't operating then it seem like theres a common fault thats inhibiting power to the actuator and pump relays - is there fuse somewhere. 

Have the actuators got two or four wires. Two wire types are just actuators wheras four wire means they've got a microswitch but it seems unlikely that they've all packed up at the same time. So dont go changing them all. Its possible that one has failed and taken out a fuse (I had that happen on one of my manifolds)

 I'm guessing that all the actuators are pretty similar a PTC heater heats a wax pellet which pushes out the operating pin - mine are Polypipe so you dont really have to change them with your specific brand.

the manual for the UH!-W isn't everso helpful - download one form the interweb if you haven got one.

Hi, thanks for comment. I have changed the F1 fuse and all working now except a couple of actuators - I've ordered a few of the Emmeti actuators. These one's I have are about 14 years old so they've done well. I actually changed out the UH1-W last night because one of the capacitors on the PCB has a wee dome shape, fortunately I have a couple of spare UH1-W's that I got cheap on Fleabay, never been used, about £60 each. Another concern  is the 3-port valve in my IVT Greenline HT Plus E7. The underfloor heating pressure has been rising a lot when the GSHP is heating domestic water. I thought the 3 port valve was stuck. Opened the machine and going by the red position disk on the motorised valve, the valve is just continually turning. I hope it's just a micro switch inside the motor that's causing it and not the heatpump controller - they don't make that controller any more. I have ordered a new 3 port valve from ALTO Spares, unfortunately they won't sell the motor on it's own. This will be the 2nd 3 port valve I've changed in over 14 years - I'm hoping the valve body itself is good, hopefully I can just change the motor part this time.

matelodave

so problem sort of solved then -