Harrow · HA1, HA2 and HA3
Power Flush Harrow
Harrow is a big borough with a lot of family homes, and a great many of them were built within a couple of decades of each other. That means we see the same heating patterns over and over — and have learned what works for Harrow’s housing.
Heating systems in Harrow homes
Around Harrow on the Hill, near Harrow School and the historic High Street, there are older period houses. Spreading out from there — through Kenton, Harrow Weald, Rayners Lane and Wealdstone — are the interwar Metroland suburbs, with row after row of semi-detached houses built as the railway and Underground lines opened up the area.
Harrow’s interwar semis have often been extended and had their loft converted, so systems that were designed for six or seven radiators now serve ten or more. Many have also switched from open-vented systems to combi boilers. When that conversion was done without a thorough clean, old sludge ended up in the new boiler.
Common heating problems we see in Harrow
- Undersized systems after extensionsMore radiators than the system was designed for, with circulation that suffers badly once sludge builds up.
- Combi conversionsOpen-vented systems converted to sealed combis without a thorough system clean.
- Kettling boilersLimescale and sludge in the heat exchanger making the boiler rumble and bang.
Other signs to look out for include black water when you bleed a radiator, a boiler that bangs or “kettles”, and radiators that take a long time to warm up. Our guide to signs you need a power flush covers them in more detail, and if your radiators are cold in particular, start with cold radiators: causes and fixes.
Our power flushing service in Harrow
Here’s what a power flush from us involves in Harrow:
- We check the system and test the water to confirm a flush will help.
- The power flushing machine is connected and cleaning chemicals circulated.
- Each radiator is flushed on its own, with flow reversal and agitation.
- Dirty water goes to drain until the system runs clean.
- Inhibitor is added and the system recommissioned and checked.
Read the full detail on our power flushing service page, or see what affects the cost of a power flush. If you’re about to replace your boiler, see power flushing before a new boiler.
assets/img/photos/power-flush-before-after-water.webpBooking a power flush in Harrow: practical details
Parking around Harrow town centre and Harrow on the Hill is controlled, while suburban roads in Kenton, Harrow Weald and Rayners Lane are generally easier. In extended houses, a quick sketch or list of which rooms have radiators — including the extension and loft — helps us quote accurately.
On the day, the heating and hot water will be off for most of the working day. It helps to clear space around the boiler and radiators, and to tell us about any radiators that are hard to reach.
Areas near Harrow we also cover
See all the areas we cover across London.
Power flushing in Harrow: FAQs
Do you cover Kenton and Wealdstone?
Yes, along with Harrow on the Hill, Harrow Weald, Rayners Lane, North Harrow and the surrounding HA1, HA2 and HA3 areas.
We converted to a combi years ago and the boiler keeps faulting. Could it be sludge?
It’s one of the most common causes we see. If the system wasn’t cleaned at the conversion, debris can block the combi’s heat exchanger and diverter valve. A water test will show whether contamination is likely.
Can you fit a magnetic filter too?
Yes — we usually recommend one after a flush. See our magnetic filter page for details.
Book a power flush in Harrow
Send us your postcode and a few details about your heating, and we’ll give you honest advice and a clear quote.