Case Study: A Tired British Gas 330 Replaced Properly in Weybridge
A boiler replacement in Weybridge that shows the difference between hanging a new boiler on an old system and doing the job right — new Greenstar Ri, full flush, a header tank you have to see to believe, and a filter fitted where it can actually be serviced.
The job
The customer's British Gas 330 — a boiler that had served them well enough but was now old, tired and increasingly expensive to keep going — needed replacing. The obvious job is a like-for-like swap: old boiler off the wall, new one on, connect it up, done in a day.
The problem with the obvious job is what it ignores. A new boiler connected to a dirty system inherits every problem that system has — and this one had a loft tank full of rust that had been circulating through the radiators for years. So this became a system job, not just a boiler job.
Step by step
1. The old boiler
The British Gas 330 in its cupboard, end of its useful life.
2. The bit most people never see: the header tank
On an open-vented system the feed-and-expansion tank in the loft tops the heating up and takes the expansion. It's out of sight and, in most homes, out of mind — which is how it ends up like this. That rust and sludge doesn't stay in the tank: it circulates through every radiator, the pump and the boiler's heat exchanger.
The tank was drained, cleaned out properly and the ball valve checked, so the system is topping up with clean water from now on rather than re-seeding itself with rust.
3. Full system flush
With the tank dealt with, the whole system was flushed before the new boiler was connected — the only way to be sure the new heat exchanger isn't being fed the old system's debris from day one.
4. A filter you can actually get to
A magnetic system filter catches whatever the flush didn't and protects the boiler for its whole life — but only if it's emptied at every service, and that only happens if it's reachable. So the return was re-piped to put the filter somewhere accessible rather than tucked out of reach. A small detail on installation day that matters every year after.
5. The new boiler: Greenstar Ri ErP
The replacement is the Worcester Bosch Greenstar Ri ErP: a regular (heat-only) boiler working with the existing hot water cylinder — the right fit for this home rather than an unnecessary combi conversion — commissioned, Gas Safe notified and registered with Worcester Bosch for the manufacturer warranty.
The result
A new boiler on a clean system with a serviceable filter guarding it, and a manufacturer warranty that stays valid with an annual service — booked into my diary, with a reminder to the customer before it's due. The gap between this and a like-for-like swap is maybe a day's extra work; the gap in how long the boiler lasts is measured in years.
Job summary
Replacing a boiler in Weybridge?
Weybridge has a lot of homes with open-vented systems and header tanks that haven't been looked at in decades — if yours is one of them, the boiler is rarely the only thing that needs attention. I survey the whole system, tell you what genuinely needs doing and what doesn't, and quote it in writing. Full details on the boiler installation page, or read about heating services in Weybridge. I also cover Walton-on-Thames, Addlestone, Chertsey, Byfleet and the surrounding towns.