No hot water in Knebworth? Boiler repairs sorted properly
No hot water but heating still works? On a combi, that's almost always a diverter valve, diaphragm or PCB issue. We carry the common parts, diagnose on-site and usually get it fixed in one visit across Knebworth. Most Knebworth repair callouts we diagnose and fix on the first visit — common parts (PRVs, diverters, pumps, PCBs) live on the van.
You're not getting a call centre — you're getting Grant.
The same engineer quotes the job, does the work, and answers the phone afterwards if anything's not right.
Gas Safe Registered
Every gas job legally signed off
18+ years on the tools
Grant has been fixing boilers in Harlow since before smart thermostats existed.
Real human on the phone
Most calls answered the same day, often within the hour.
Locally based in Knebworth
Not a national chain — your local engineer, your local prices.
No hot water but heating still works? On a combi, that's almost always a diverter valve, diaphragm or PCB issue. We carry the common parts, diagnose on-site and usually get it fixed in one visit across Knebworth. Most Knebworth repair callouts we diagnose and fix on the first visit — common parts (PRVs, diverters, pumps, PCBs) live on the van.
From first call to handover — our boiler repairs routine
Fast response
Same-day where possible — especially for vulnerable customers or no-heat in winter.
Honest diagnosis
If your boiler is past saving, we'll tell you. We won't sell you a £400 repair on a 16-year-old unit.
Repair, replace, or part-exchange
Three options where appropriate, with honest cost/benefit on each.
Aftercare
We log the repair, register the parts warranty, and give you a service reminder.
What's included
No Hot Water Repair
Diverter valves, diaphragms, PCBs — the common combi hot water faults.
Learn moreNo Heating Repair
Pump faults, airlocks, frozen condensates — getting heat back on quickly.
Learn moreLeaking Boiler Repair
Pressure valves, heat exchangers, pump seals — sealing leaks safely.
Learn moreBoiler Fault Code Diagnosis
F1, F22, EA, A01 — translating fault codes into real fixes.
Learn moreWhat makes our boiler repairs work different in Knebworth
Three things Hertford customers tell us they value: we turn up when we say we will, we explain things in plain English, and we don't try to sell you anything you don't need.
For boiler repairs specifically, that means honest advice on whether to repair, replace, or upgrade — not a default sales pitch.
Everything we do is Gas Safe registered, fully insured, and backed by a 12-month workmanship guarantee.
About Knebworth
Large village at the southern edge of Stevenage with strong commuter housing — Edwardian, inter-war and modern estate stock.
Edwardian, inter-war and modern. Strong mains gas.
- Conservation area constraints in centre
- 60s-built systems on second replacement cycle
- Older listed property compliance
What you get when you book us
- Fixed price before any work starts
- All major brands — Worcester, Vaillant, Ideal, Baxi, Glow-worm
- Vulnerable household priority response
- Honest 'is it worth fixing?' advice
- Same-day response wherever possible
boiler repairs in Knebworth: questions we get a lot
Why have I lost hot water but heating still works?▾
On a combi boiler this is the classic diverter valve symptom — the valve that switches the flame between heating and hot water has stuck. Common, and usually a one-visit fix.
How much will it cost?▾
Diverter valve replacement on most boilers is £180–£320 fitted. We'll give you a fixed price after diagnosis before any work starts.
Do you charge a callout fee?▾
We charge a clear diagnostic fee (told to you upfront before we attend). It covers proper on-site diagnosis. The repair itself is then quoted as a fixed price you agree before any work starts.
Is it worth repairing an old boiler?▾
Honest answer: if it's over 12 years old and the repair is more than £400, replacement usually makes more financial sense. We'll lay out both options without pressure.
What else we can help with in Knebworth
Boiler installs in Knebworth
Worcester, Vaillant, Ideal and Glow-worm boilers fitted by Gas Safe registered engineers — sized properly, fitted neatly, and backed by manufacturer warranties of up to 12 years.
Boiler servicing in Knebworth
Annual servicing keeps your boiler safe, efficient, and your manufacturer warranty valid. Full inspection, combustion analysis, and a written report.
Heating upgrades in Knebworth
Cold radiators, noisy systems, sky-high bills? Power flushes, smart thermostats, radiator swaps and full system upgrades that pay for themselves.
Plumbing in Knebworth
Everyday plumbing done properly — taps, toilets, leaks, washing machines, showers, outside taps and isolation valves.
Our coverage around Knebworth
At a glance
- Service
- Boiler Breakdowns & Repairs
- Coverage
- Hertford (SG13, SG14) and surrounding areas
- Response time
- Usually within 24–48 hours
- Credentials
- Gas Safe registered, fully insured, 12-month workmanship guarantee
- Pricing
- Fixed written quotes, no surprise extras
Roughly what you'll pay in Knebworth
These are honest starting prices for jobs we do every week. Final quote depends on your property — we'll always confirm in writing before any work starts. No surprise add-ons.
| Job | Price |
|---|---|
Diagnostic call-out first hour on-site, transparent before any parts | from £85 |
Common parts (PCB, fan, pump) fitted same-visit where possible | £140–£380 |
No-heat / no-hot-water emergency same-day priority slot | from £120 |
Quote over the phone send a photo of the fault code | free |
Prices include VAT. Parts quoted separately and shown on your written quote.
Other ways Knebworth customers find us for boiler repairs
Same engineer, same fixed pricing — different question, different answer.
Hot water sorted in Knebworth
Free written quote, no obligation. Real engineer, fixed price, fast response.