When central heating stops working properly — whether it is patchy, weak, or not coming on at all — there are usually a few likely causes. Call 020 7183 4810 and we will diagnose it properly.
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Common causes of central heating problems
- Trapped air or sludge in the system
- A failing pump or valve
- Thermostat or timer issues
- Boiler pressure problems
- A circuit or zone valve fault affecting specific rooms
A few things you can safely check first
- Thermostat settings and battery (if applicable)
- Boiler pressure gauge reading
- Whether the issue affects the whole house or just some rooms
Beyond these basic checks, diagnosing pump, valve or wider system faults needs a proper inspection.
Why we do not recommend the popular online fixes
| Common online advice | Why it falls short |
|---|---|
| “Bleed every radiator in the house” | Fixes trapped air but not pump, valve or sludge issues, which are common causes of patchy heating. |
| “Replace the thermostat yourself” | Often the thermostat is not the actual fault, and incorrect wiring can create a bigger problem. |
Stop and call us if…
- Some rooms heat and others do not
- The heating is not coming on at all
- You hear banging, gurgling or whistling from pipework
- Boiler pressure keeps dropping alongside the heating issue
What it costs to wait
An inefficient heating system costs more to run and puts extra strain on the boiler and pump, which can lead to a bigger repair bill down the line.
How Olia’s Plumbing & Heating handles it
- Call 020 7183 4810 and describe the issue
- Our engineer inspects the whole system, not just one radiator
- We identify the actual cause and quote before repairing
Get your heating diagnosed properly
Fast, reliable repairs across London.
Frequently asked questions
Why is only part of my house heating?
This is often a valve, pump or balancing issue rather than a boiler fault — our engineer can identify which.
How much does a heating repair cost?
It depends on the cause. Call 020 7183 4810 for a clear price after diagnosis.
Should I try a power flush myself?
No — this requires specialist equipment and is best left to a professional to avoid damaging the system.
Do not keep guessing at the cause. Call 020 7183 4810 for a proper diagnosis.
Related services: How to Bleed Radiators Properly, Boiler Repair Central London, Underfloor Heating Service Central London
Peyman
CEO & Founder — Gas Safe Registered Engineer
Peyman is the founder of Olia's Plumbing & Heating, a London based team with over 15 years of hands on experience in boiler installation and repair, central heating, gas work and emergency plumbing. He personally oversees jobs across Central and West London and writes these guides to help homeowners understand their heating systems.
- Gas Safe Registered
- 15+ years experience
- Covering all of London
