Combi Boiler Replacement in GU21 — Same-Week Booking
A like-for-like combi swap in Woking is a one-day job — arrive at 8am, hot water back on by 4pm, dust sheets rolled up, old boiler gone by 5pm. We do 6-8 of these a week across GU21, so the process is well-oiled: survey, quote, order, fit, commission, register the guarantee. Most Woking customers are on Worcester Bosch Greenstar 4000 or 8000 depending on hot water demand and budget.
Why this matters in Woking (GU21)
Woking has a lot of town-centre flats, which tend to have first-generation combis fitted in the mid-2000s that are now 18-20 years old. Sensible replacement window is now — not because they've failed yet, but because parts availability drops sharply after 15 years and one bad winter's worth of breakdown callouts costs more than the new boiler.
Combi boiler replacement in Woking — at a glance
- Like-for-like Greenstar 4000 combi
- £1,895-£2,395
- Upgrade to Greenstar 8000
- +£500-£800
- First-time conversion (2 days)
- £2,995-£3,995
- System flush + magnetic filter
- Included
- Typical GU21 lead time
- 5-10 working days
Combi replacement done properly in Woking
- Worcester Bosch Accredited — 10-12 year guarantees
- Same-day heating and hot water on like-for-like swaps
- Building Regulations notice filed with Gas Safe automatically
- Old boiler and packaging removed and disposed of
Combi boiler replacement FAQs for Woking
How long does a combi swap take in a Woking home?+
Like-for-like same-position swap: one day, 8am to 4pm. Position change or first-time conversion: two days. Full system change with cylinder removal: 3-5 days. Every timeline written into the quote before we start.
Will I have heating and hot water the same day in Woking?+
Yes for a like-for-like combi swap — heating and hot water are usually back on by 4pm. For conversions, we plan the second day so overnight hot water is available via the immersion or an alternative arrangement.
What size combi do I need in Woking?+
Depends on your bathrooms and hot water demand, not the house size. 1 bathroom = 25kW, 2 bathrooms = 30kW, 3+ bathrooms = 35-42kW. We measure incoming mains flow rate at survey — a bigger boiler on a weak main is wasted money.
Should I go for the Greenstar 4000 or 8000 in Woking?+
4000 is our workhorse — proven, cheaper, 10-year guarantee. 8000 is the premium option with a bigger heat exchanger, quieter operation and the 12-year guarantee. For most town-centre flats the 4000 is the honest recommendation; the 8000 makes sense for larger family homes.
Can I keep my existing radiators when the combi is replaced in Woking?+
Yes — we power flush the existing system as part of the install (or fit a chemical clean and magnetic filter, depending on sludge level). Radiators older than 25 years occasionally need replacement, but most keep working fine.
More Woking guides
A combi replacement in Woking is a one-day, one-team job when done properly. Book a free survey, get a fixed-price written quote inside 48 hours, and pay 0% APR over 24 months if you'd prefer to spread the cost.