Npower / Servowarm Boiler Repairs London

Npower / Servowarm Boiler Repair Help Centre

Npower and Servowarm boiler faults, safe checks, and honest advice — you do not need Npower for repairs.

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Quick Checks ·
Common Faults ·
Parts Situation ·
Repair or Replace

You Do Not Need Npower for Boiler Repairs

If you have an Npower-branded or Servowarm boiler, you might think you need to contact Npower for repairs. You do not. Any Gas Safe registered engineer can repair your boiler.

Npower (now part of E.ON) sold boilers under their own branding, but these were typically manufactured by established boiler makers. Servowarm was a separate brand that is also now discontinued. In both cases, the boilers are standard gas appliances that any competent Gas Safe engineer can diagnose and repair.

Identifying Your Boiler

To help us diagnose your boiler faster, check the data plate (usually inside the front panel or underneath the boiler). This will show:

• The model name/number
• Sometimes the original manufacturer
• Serial number and GC number

If your boiler shows a different manufacturer name alongside Npower or Servowarm branding, let us know — this helps us identify compatible parts.

Quick Checks Before You Call Anyone

These basic checks apply to most boilers and may resolve simple issues:

1. Check the pressure gauge (if fitted): If below 1 bar, you may need to top up. If you are unsure whether your system is sealed or open-vented, do not attempt to add pressure. More detail in our complete pressure guide.
2. Note any fault indication: Write down or photograph any error codes, flashing lights, or display messages.
3. Check your fuse box: Boilers need electricity; a tripped breaker can look like a boiler failure.
4. Check thermostat and timer: Settings can change after power cuts or clock changes. Dead batteries in wireless controls can stop heat calls.
5. Freezing weather? On condensing boilers, the condensate pipe can freeze. See our frozen condensate guide.
6. Reset once only: If there is a reset button, press it once and wait 60 seconds. If the boiler locks out again, stop and call an engineer.

Common Npower / Servowarm Boiler Problems

These boilers tend to be older installations and experience typical age-related issues:

Ignition failure / no flame: The boiler attempts to light but cannot establish a stable flame. Common causes include worn ignition components, faulty gas valves, or frozen condensate pipes in winter.

Low pressure / pressure loss: On sealed systems, pressure dropping frequently usually indicates a leak somewhere in the system, or an expansion vessel / pressure relief valve issue.

No heating or hot water: Could be a diverter valve problem (on combis), pump failure, motorised valve issue, or a control/thermostat fault.

Strange noises: Banging, kettling, or gurgling can indicate sludge buildup, limescale, trapped air, or pump problems. Read our guide to boiler noises.

Leaking: Water from the boiler case, underneath, or from the pressure relief valve discharge pipe needs prompt attention.

PCB / control faults: Random lockouts, display issues, or erratic behaviour can indicate control board problems.

Parts Situation

Parts availability depends on the original manufacturer:

• Generic parts (pumps, motorised valves, thermostats, some sensors): Usually still available
• Brand-specific parts: May be available if we can identify the original manufacturer; otherwise difficult
• Servowarm-specific parts: Increasingly scarce as the brand has been discontinued for many years

If we can identify the original manufacturer from your boiler’s data plate, parts sourcing becomes much easier. Many “energy supplier branded” boilers were made by companies like Vaillant, Worcester, Baxi, or Potterton.

Repair or Replace?

For most Npower and Servowarm boilers, age is a key factor:

Repair may make sense if:

• The fault is simple (thermostat, controls, ignition component)
• The required part is available
• The boiler has otherwise been reliable
• You need a short-term solution while planning replacement

Replacement is usually smarter if:

• The boiler needs a part that cannot be sourced
• You have had multiple breakdowns in the past 12 months
• The boiler is over 15 years old
• Efficiency has noticeably declined (higher bills, slower heating)
• You want reliability and a proper warranty

A modern condensing boiler will be significantly more efficient than an older unit, potentially reducing your gas bills by 20-30% or more.

We give honest advice either way. Read more: Repair or replace? An engineer’s guide.

If you decide on a new boiler: New boiler installation.

What Happens When You Call Us

If you have an Npower or Servowarm boiler:

1. We will ask about the symptoms and any fault codes
2. We will ask you to check the data plate for model/manufacturer info
3. We will be upfront about likely parts availability
4. Our engineer will diagnose the fault and assess repairability
5. We will give you honest options: repair (if viable) or replacement

Boiler Servicing

If your boiler is still running well, annual servicing can help keep it that way. Servicing also gives us a chance to spot developing issues before they become breakdowns.

Book your boiler service.

Renting? Landlords: Check This

Tenants: Your landlord is usually responsible for boiler repairs. Contact them first and keep written records.

Landlords: If your rental property has an older Npower or Servowarm boiler, consider proactive replacement to avoid emergency call-outs and parts availability issues. Stay compliant with our Gas Safety Certificate (CP12) service. See our London landlord checklist.

London Wide Coverage

We diagnose and repair boilers across all London boroughs including North, South, East, West, and Central London.

For coverage and service areas, see our London coverage page.

We Repair All Major Boiler Brands

What We Need From You (To Diagnose Faster)

• Boiler model: Check the data plate for model name/number and any manufacturer info
• What is happening: No heating, no hot water, leaking, noises, fault codes
• Any fault indication: Error codes, flashing lights, or display messages
• Approximate age: When was it installed (if known)?
• Postcode: So we can route the closest engineer

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