Underfloor Heating

Underfloor Heating Fault Diagnosis

Underfloor heating can fail for several reasons, from a stuck actuator or air in the circuits to pump, control, or balancing problems. This fault diagnosis service is designed to identify the root cause of issues in wet underfloor heating systems, so you can make an informed decision on the most effective repair or adjustment.

More information

What the diagnosis covers

A structured check of the key components that affect heat output, flow, and control. The goal is to move from symptoms to a clear, practical answer.

  • Review of symptoms and system layout (zones, manifold, controls)
  • Visual checks for leaks, corrosion, damaged valves, and obvious installation issues
  • Manifold inspection: flow meters, isolation valves, air vents, and return temperatures
  • Pump and circulation checks where applicable
  • Zone operation checks: actuators, thermostats, wiring centre, and control signals
  • Pressure and airlock investigation (common cause of cold loops)
  • Basic system balancing assessment to improve even heat across rooms
  • Clear explanation of findings and recommended next steps

When this service is most useful

Book a diagnosis if:

  • One room or zone is cold while others work
  • The system takes far longer than usual to warm up
  • Floors feel patchy, with hot and cold areas
  • Thermostats call for heat but nothing changes at the floor
  • You have frequent pressure drops, topping up, or repeated air in the system

What to expect during the visit

The engineer will ask a few questions about the fault history, recent changes, and how the system is controlled. Tests then focus on the manifold, pump, and controls to confirm whether the issue is flow related, control related, or linked to a specific circuit. Where access allows, checks are kept as non disruptive as possible.

After the diagnosis

You will be talked through what was found in plain English, with options to resolve it. If a repair is needed, you can expect a clear scope of work, likely parts required, and any follow on improvements such as rebalancing or control adjustments to prevent repeat problems.

Frequently Asked Questions

Do you diagnose electric underfloor heating as well as wet systems?
This service is for wet (water based) underfloor heating connected to a manifold and heating system. If you are unsure which type you have, describe what you can see and we can advise before booking.
Will you need to lift floors to find the fault?
In many cases, no. A lot of faults are traced to the manifold, pump, airlocks, valves, or controls that can be tested without lifting finishes. If intrusive work is the only sensible next step, you will be told why before anything is done.
How long does an underfloor heating diagnosis take?
Timing depends on the number of zones, accessibility of the manifold, and how the system is controlled. Simple issues can be confirmed quickly, while multi zone faults may take longer to test and isolate.
Can the problem be fixed on the same visit?
Sometimes, yes, especially for issues like air in the system, minor control adjustments, or a stuck valve. If parts are required or the fault is in a less accessible area, you will be given a clear plan for the repair.
What if the fault is actually with the boiler or central heating controls?
Underfloor heating performance can be affected by the heat source and primary controls. If the diagnosis indicates an issue outside the underfloor circuits, you will be advised on what needs attention and the most efficient way to address it.

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