Underfloor Heating Repair

The parts that fail on underfloor heating, in plain English

• Pump: on the manifold, moves the water round the loops. The most common part to fail outright. A cold floor with a hot manifold usually means the pump.
• Mixing valve: blends boiler water down to floor temperature. Sticks or drifts, giving a floor that's lukewarm or, less often, too hot.
• Actuators: the small motors on each loop. Fail one at a time. One dead actuator means one cold room.
• Thermostats: batteries, wiring or the stat itself. A room that never calls for heat is often a thermostat, not the floor.
• Wiring centre: connects stats to actuators and the boiler. A fault here can look like several rooms failing at once.
• Air in the system: collects at the top of the manifold and in high loops. Gurgling, a noisy pump and patchy heat.
• Pressure: a slow drop points to a weep at a manifold fitting. A fast drop is rarer and needs finding.
• Flow gauges: the little sight glasses on each loop. Stuck or dirty ones make a working loop look dead.
• Boiler or heat pump: if the heat source isn't firing for the floor, nothing at the manifold will fix it.
• The pipe under the floor: almost never the fault. It's checked last, not first.

What usually goes wrong, and what fixing it involves

• Underfloor heating not heating up at all: check the boiler is firing and the pressure is up. Then it's usually the pump or the wiring centre. A pump swap is about an hour, from £99 plus the part.
• One zone cold, the rest fine: the actuator for that loop, or its thermostat. An actuator is a ten minute swap; a thermostat a little longer.
• Floor warm in patches: air in the loops or a loop out of balance. Bleeding the manifold and rebalancing is a short visit and often no parts at all.
• Floor takes hours to warm up: mixing valve set too low or blocked filters. Both fixed on the visit.
• Noisy manifold or pump: air, or a pump bearing on its way out. Bled on the day, or a new pump if it's failing.
• Pressure keeps dropping: a weep at a manifold fitting nine times out of ten. Nipped up or the fitting replaced. If the manifold is dry, we pressure test the loops before anyone talks about the floor.

Honest advice: what's overkill

• Taking the floor up: the last resort, not the first. A loop under the floor almost never fails, and a pressure test proves it before a single tile is touched.
• A new manifold for one failed part: pumps, mixing valves and actuators all come off and go on individually. The manifold body lasts decades.
• A whole new control system for one thermostat: replace the thermostat that's failed. If you want smart control later, that's a separate decision, not a repair.
• A specialist underfloor firm for a manifold fault: any heating engineer who knows manifolds does this on a normal call out, for a normal price.
• Worth paying for: an annual service. Nearly every repair on this page would have been caught on a £99 service before it left you with a cold floor in January.

When to call

Check the boiler is on and the pressure is above 1 bar. If it is and the floor's still cold, or a room's not heating, message us a photo of the manifold and what the floor's doing. Contact me now