Gledhill Pulsacoil and Boilermate Repair in London
We repair, service and replace Gledhill thermal stores across London, and convert them to mains pressure unvented cylinders when repair stops making sense.
Book a Plumber Call 020 3764 2713✓G3 qualified engineers✓Pulsacoil and Boilermate✓Thermal store conversions✓London, inside the M25
Thermal store specialistsNot just cylinders, and not just HIUs
G3 qualifiedRequired by law for unvented work
4.96 / 5From 1,200+ verified TrustATrader reviews
24 hours a dayEvery borough inside the M25
WHAT YOU ACTUALLY HAVE
A thermal store heats water differently from a cylinder
It looks like a cylinder, which is why most people assume it is one. The difference matters when it breaks.
How it works
A normal cylinder stores the hot water you wash in. A Pulsacoil or Boilermate stores heated water that never leaves the unit. Your cold mains passes through a heat exchanger inside the store and picks up heat on its way to the tap.
Why it was fitted
You get hot water at mains pressure without a pressurised vessel, which is why these units went into so many London flats where a loft tank was impossible and an unvented cylinder was not wanted.
Why it matters now
That design changes which parts fail. The components that go wrong on a thermal store are not the ones that go wrong on a cylinder, and a plumber who has only worked on cylinders will often struggle with one.
MODELS
Units we work on
If you are not sure which you have, the model name is on a label on the front. Send us a photo on WhatsApp and we will tell you.
Pulsacoil range
- Pulsacoil III
- Pulsacoil A-Class
- Pulsacoil Stainless
Boilermate range
- Boilermate 2000
- Boilermate A-Class
- Boilermate OV
- Boilermate SP
Not sure it is either?
Many London blocks run communal heating, where heat arrives through a heat interface unit instead. The symptoms overlap almost exactly. HIU service and repair →
DIAGNOSIS
Faults we see most
Six problems account for almost every Pulsacoil and Boilermate call we take.
No hot water, heating still fine
Usually an immersion heater that has burnt out, or its thermal cut-out having tripped. These units lean hard on their immersion elements, so elements are the most common single failure.
Hot water goes lukewarm
The store is not reaching temperature, or the heat exchanger has scaled up and no longer transfers heat properly. London water is hard, and scale builds on the hottest surfaces first.
Hot water runs out fast
One of two immersion heaters has failed, so only part of the store is heated. It works until the heated section runs out, which is why it feels like the unit has shrunk.
Noise from the unit
The internal pump on its way out, or scale on the heating surfaces causing local boiling. Worth attending to early, because a seized pump usually takes the hot water with it.
Controls dead or erratic
The control board. On older Pulsacoil units these are the hardest part to source, and a failed board is often where replacing the whole unit becomes the better spend.
Water around the base
A connection, an immersion boss gasket, or the store itself. The first two we repair. If the store has corroded through it cannot be patched and the unit needs replacing.
THE DECISION
REPAIR OR REPLACE
We will give you a straight answer, not a quote for whichever is dearer
Can we get the part. Spares for the older ranges are harder to source every year. Immersion heaters and thermostats are still straightforward. Control boards and pumps for the early units are not always available, and a unit you cannot get a board for is a unit on borrowed time.
What it costs you to run. Most of these units heat on immersion elements, which means making hot water on electricity. If yours is heating on peak rate rather than off peak, that is often the largest line on the bill in a one bedroom flat.
How old it is. If the unit is twenty years old, the board has gone and the elements have been changed twice, another repair buys you a year. Converting to a modern unvented cylinder buys you twenty, with a 25 year guarantee on the shell provided it is serviced annually.
Worth repairing when
- The fault is an element or a thermostat
- Parts are still available for your model
- The store itself is sound
- Running cost is already on off peak
Worth replacing when
- The control board has failed on an older unit
- The store is leaking from the body
- You are paying peak rate for every bath
- It has already been repaired twice
UPGRADE PATH
Converting a thermal store to an unvented cylinder
This is the upgrade most people are after, and it only works if the mains supply will carry it.
What we measure first
- Dynamic pressure with water running: at least 1.5 bar
- Flow rate: at least 20 litres per minute
- Incoming main: 22mm copper or 25mm MDPE
Standing pressure alone tells you very little. A flat can show 4 bar standing and still fail. How we test →
What you gain
A thermal store already gives you mains pressure hot water, so the gain is in reliability, running cost, and parts you can still buy in ten years. A modern stainless steel unvented cylinder has no control board, no internal pump and no heat exchanger to scale up.
The paperwork
Installing an unvented cylinder over 15 litres is notifiable under Part G3. We self certify through a Competent Person Scheme, so you get a Building Regulations compliance certificate plus a signed Benchmark checklist. Keep the Benchmark, or the manufacturer guarantee is void.
HOW IT WORKS
From first call to working hot water
1
Send us a photo
The label on the front tells us the model. Send it on WhatsApp or through the contact form and we will tell you what you have.
2
We attend and diagnose
A G3 qualified engineer tests the elements, thermostats, pump and controls, and tells you which has failed rather than guessing at the whole unit.
3
Repair, or an honest replacement case
If the part is available and the store is sound, we repair it. If it is not, we explain why and what a conversion would give you.
4
Certified and documented
Unvented installations come with a Building Regulations compliance certificate and a signed Benchmark commissioning checklist.
Is a Pulsacoil a boiler or a cylinder?
Neither. It is a thermal store. It holds heated water that stays inside the unit, and heats your mains water on demand as it passes through. There is no boiler inside it and no pressurised cylinder in it.
Can you still get parts for a Pulsacoil III?
For some parts, yes. Immersion heaters and thermostats are generally available. Control boards and pumps for the older units are the difficulty, and availability has been getting worse. We will tell you on the visit whether the part your unit needs can be sourced.
Why is my Boilermate so expensive to run?
Because it makes hot water with electricity rather than gas. If it is heating on a peak rate tariff rather than off peak, you are paying the most expensive rate available for every bath. Check which tariff you are on and which heating period the unit is set to. That costs nothing and it is the first thing to rule out.
Can I replace my thermal store with a normal cylinder?
Usually, if the cold mains will support it. We need 1.5 bar of working pressure, 20 litres per minute of flow, and an incoming pipe of at least 22mm. We test all three before quoting. If the supply falls short, an accumulator can often make up the difference.
Do I need a G3 engineer for a thermal store?
A thermal store is not a pressurised vessel, so G3 does not apply to it the way it applies to an unvented cylinder. The moment you replace it with an unvented cylinder, it does. All our cylinder engineers hold a current G3 qualification either way.
Which London areas do you cover?
Every borough inside the M25. Our engineers are mobile and dispatched directly to you, and we take calls 24 hours a day.
Not sure what is in that cupboard?
Send us a photo of the unit and the label on the front. We will tell you what it is, what is likely wrong with it, and whether it is worth repairing.
Book an AppointmentCall 020 3764 2713Send a PhotoRelated services
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