Underfloor Heating Not Warming Up
The floor stays cool despite the system running and the manifold being warm..
The floor stays cool despite the system running and the manifold being warm.
What is actually going on
The floor stays cool despite the system running and the manifold being warm.
The realistic causes, in order
An actuator that has failed closed on that loop, so no flow reaches the circuit Air locked in a loop, which underfloor circuits are prone to because of their length A blending valve set too low, or a pump that isn't running on the manifold
What we test on site
Flow meter readings on each loop at the manifold Actuator operation on each zone under demand Blending valve setting and manifold pump operation
Safe checks to make with underfloor heating that won't warm up
- Feel the manifold flow and return pipes for each loop and note which are cool
- Check the zone actuators aren't all still in a closed position
- Underfloor circuits run at lower temperatures than radiators and must be blended down. Running them at full boiler flow temperature can damage floor finishes.
Who does the work
- Gas Safe registered engineers — registration 554328
- Worcester Bosch accredited installer
- John The Plumb Ltd, company registration 10026483
Get underfloor heating that won't warm up diagnosed properly
Purging loops, replacing actuators and re-balancing the manifold normally restores even floor temperature.
Questions we get asked
What causes underfloor heating that won't warm up on a gas boiler?
An actuator that has failed closed on that loop, so no flow reaches the circuit
What normally puts underfloor heating that won't warm up right?
Purging loops, replacing actuators and re-balancing the manifold normally restores even floor temperature.
Is it safe to keep using the system with underfloor heating that won't warm up?
Underfloor circuits run at lower temperatures than radiators and must be blended down. Running them at full boiler flow temperature can damage floor finishes.