Immersion Heater ReplacementSame-Day Where PossibleBolton & Manchester
Failed immersion heaters replaced quickly — we carry common 3kW elements in stock for same-day fitting in most cases. Suitable for both vented and unvented hot water cylinders.
Common sizes in stock • Same-day where possible • G3 qualified
Common Sizes
Stock
Same-Day
Service
Vented & Unvented
Cylinder Types
G3 + Gas Safe
Qualification
Workmanship
Guarantee
When Your Immersion Fails — Fixed Fast
An immersion heater is a sealed electric heating element fitted into the side of your hot water cylinder. It's either your primary hot water source (in homes without a boiler-fed cylinder) or your back-up for when the boiler is off.
When the element fails — and they do, usually through scale build-up or thermostat failure — you're left with no hot water until it's replaced. We carry common sizes (11" and 14", 3kW, both standard and Incoloy for hard water) on every van for same-day fitting in most cases.
Replacement involves isolating power, draining enough of the cylinder to expose the element, unscrewing the failed unit, fitting the replacement with a new fibre washer, refilling and testing. Typically 45-60 minutes once we arrive.
Real Work Examples
Why Immersion Heaters Fail
The most common cause of immersion failure in our area is scale build-up — Bolton and Manchester have moderately hard water, and limescale coats the element, eventually causing it to overheat and burn out.
Less commonly, the thermostat fails (no heating despite a working element) or the seal at the cylinder boss leaks. Both are usually fixable as part of the same visit.
- Scale build-up is the leading cause of failure — Incoloy elements last longer in hard water
- A tripping immersion circuit usually indicates a failed element, not a wiring fault
- If both elements (where fitted) fail at the same time, check the thermostat or wiring first
- Replacing the immersion is a good time to also replace the gasket and check the anode
- Old cylinders sometimes have seized immersion bosses — patience and proper tools needed
Our Process
Isolate
Power to the immersion circuit isolated at the consumer unit. Tested dead before any work begins.
Drain Down
Enough water drained from the cylinder to expose the immersion boss — usually about half the cylinder volume.
Remove Failed Element
Old immersion unscrewed from the cylinder boss (sometimes requires a specialist immersion spanner for seized fittings).
Fit New Element
New element fitted with fresh fibre washer, thermostat reconnected, wiring re-tested before refilling.
Refill, Test, Sign Off
Cylinder refilled, vented at the highest tap, power restored, heating cycle tested and outlet temperature checked.
Why Choose Conroy
Same-Day Service
Common 3kW elements in stock — most replacements done the day you call.
Hard Water Spec
Incoloy elements available — significantly longer life in our hard water area.
Both Cylinder Types
Vented (open) and unvented (sealed/pressurised) cylinders — G3 qualified for both.
Fixed Pricing
Clear upfront price covering element, washer, labour and testing. No hidden extras.
Anode & Gasket Checked
While the element is out, we check and advise on anode condition and gasket integrity — sensible preventative maintenance.
Workmanship Guarantee
All replacement work guaranteed on the workmanship we've carried out.
Technical Detail
Element Lengths
Domestic cylinders typically use 11" or 14" elements — the longer length suits taller cylinders for better heat distribution. We confirm length from the cylinder when we arrive and carry both as standard.
Standard vs Incoloy
Standard copper-sheathed elements are cheaper but scale up faster in hard water. Incoloy elements use a nickel-iron alloy that resists scaling and lasts significantly longer in Bolton, Bury and Manchester.
Thermostat Failure
Some immersion failures are the thermostat, not the element. A thermostat-only replacement is cheaper and quicker than a full element swap — we test before swapping.
Tripping RCD or MCB
A tripping immersion circuit usually means the element has broken internally and is shorting to earth. Replace the element rather than chasing it as a wiring fault.
When to Consider a Bigger Change
If your cylinder is over 15 years old, has corroded externally, or you're repeatedly replacing immersions, it may be worth quoting a new cylinder — particularly upgrading from vented to unvented for mains-pressure hot water.
Frequently Asked Questions
Looking for something else? Phil also covers 24/7 emergency plumbing, full boiler installation and boiler repairs, annual boiler servicing, central heating installation, power flushing, leak detection and landlord gas safety certificates (CP12). Browse the full list on our services page or see recent jobs and customer reviews.
Based in Bolton, we work across Bolton, Manchester, Bury, Blackburn, Chorley, Wigan, Preston and Salford. See all areas we cover, learn more about Phil Conroy, or get in touch for a free quote.
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