System balance
Quoted
Lockshield, flow-temp tuning, TRV calibration
- Full balance across every radiator
- Flow temperature tuned for system age
- TRV calibration check
- System pressure reset
- 1–2 hour visit
Plumbing
Central heating & power flushing
Radiators, system upgrades, underfloor heating, balancing and full powerflushes that cure cold-at-the-bottom rads, slow-warming rooms, and short-cycling boilers.
Pricing Quoted
Clear quote · Gas Safe registered · Checkatrade approved
- 1Send the detailsPhotos, postcode, what's happening: phone, WhatsApp or form.
- 2Same-day replyNigel confirms price, visit time or survey slot.
- 3Fixed quoteWritten down before any work starts. No surprises.
Indicative scope
Exact pricing is confirmed before work starts and depends on the property, access, parts and fault diagnosis.
Filter + inhibitor refresh
Quoted
MagnaClean fitted, X100 dosed, system balanced
- MagnaClean Pro2 or equivalent fitted
- Sentinel X100 inhibitor refreshed
- System balanced afterwards
- Magnetic plug clean before we leave
- Worcester / Vaillant warranty preserved
Full powerflush
Quoted
Full sludge removal, refresh dose, magnetic filter
- High-flow pump cycled across every rad
- Cleaning chemicals + flush samples
- Fresh Sentinel X100 dose
- MagnaClean filter included on 7+ rad systems
- 4–8 hours on site
Central heating
System running hot at top, cold at bottom?
Radiators, system upgrades, underfloor heating, balancing and full powerflushes that cure cold-at-the-bottom rads, slow-warming rooms, and short-cycling boilers.
At a glance
Quick facts before you read on.
What's included
5 things, no extras on the day- Full balance across every radiator
- Flow temperature tuned for system age
- TRV calibration check
- System pressure reset
How we quote
Confirmed before work startsFull system balance, lockshield + flow-temp tuning.
Certification
Gas Safe RegisteredJob done to standards. Paperwork on the day.
Service area
Cardiff, Penarth, Barry, CaerphillyWhen radiators are cold at the bottom and hot at the top, when one room is freezing while the rest of the house is fine, or when your boiler short-cycles every few minutes, the system needs help, not a new boiler. Most of what’s blamed on tired boilers is actually a system fault that costs a fraction to fix.
How we diagnose
Before quoting, we do a structured diagnostic visit. That means:
- Reading the flow and return temperatures at the boiler with a clamp meter.
- Checking system pressure cold and hot, and watching for drift.
- Touching every radiator at top, middle, and bottom: sludge sits at the bottom, air at the top, and the pattern tells us which problem you have.
- Sampling system water for iron content (a quick magnetic test confirms whether you have circulating sludge or not).
- Looking at the inhibitor concentration and the filter (if one exists).
Most “cold radiator” calls fall into one of three categories: sludge build-up (powerflush), air ingress (bleed and re-pressurise plus inhibitor refresh), or balance drift (lockshield re-tuning). Knowing which one you have saves a lot of money.
Powerflushing
A full powerflush removes the iron-oxide sludge that builds up in radiators and pipework over years. It’s loud, it takes a day, and it’s the difference between a system that limps along and a system that does what the manufacturer designed it for. From £480 depending on radiator count.
We use a high-flow Kamco-pattern flush pump connected at the boiler tails. Cleaning chemicals (Sentinel X400 or Fernox F5) cycle through the system in alternating directions for 4–8 hours, with samples taken every 30 minutes until the discharge runs clear. We refill with fresh Sentinel X100 inhibitor and fit (or clean) the magnetic filter before recommissioning.
We’ll always be honest about whether you actually need one. In roughly one in four of the systems we look at, a magnetic filter retrofit and a fresh inhibitor refresh will solve the same symptoms for £280 instead of £480. We’ll quote that, not the flush, when it’s the right answer.
Radiator upgrades
We replace single-panel rads with double-panel ones to recover lost output, swap in vertical rads where wall space is tight, and balance the system once we’re done so every room reaches temperature at the same time. Designer radiators (Stelrad Vita, Bisque, Reina) are typically £450–£900 fitted depending on the model.
For heat-pump conversions, we model every radiator at survey: heat pumps run at lower flow temperatures (35–55°C versus a gas boiler’s 60–75°C) so under-sized rads need upsizing, usually 3–4 radiators in a 4-bed house, sometimes none in a well-insulated post-2002 build.
Underfloor heating
New build extensions, kitchen refits, and bathroom upgrades are good moments to fit underfloor. We design and install wet UFH systems that pair properly with combi boilers and heat pumps. See the underfloor heating page for the design process and pricing.
Balancing: the cheapest fix nobody offers
Most central heating systems lose their balance over the years. Some rads heat up before others, the boiler short-cycles, the upstairs rooms never reach temperature. A proper system balance (lockshield adjustment, flow-temp tuning, TRV calibration) takes 1–2 hours and makes a real difference. £140 standalone or included free with a powerflush.
It’s an unglamorous fix, which is why most heating engineers don’t quote for it: there’s nothing big to sell on the back of it. We quote it because it’s often the right answer.
Common mistakes other firms make
- Flushing every system that walks in the door. A flush is the right answer maybe 75% of the time. The other 25% is wasted money.
- Not balancing afterwards. A flush without a balance leaves the system better but still asymmetric. We always balance after.
- Skipping the inhibitor refresh. A flush that ends with the wrong inhibitor concentration sets you up for the same problem in 3 years. We refill X100 to manufacturer spec, every time.
★★★★★
Knows what he's doing. Does what he says he'll do. Charges what he says he'll charge. Nigel is reliable and clearly a professional.
Recent jobs near you
A few of the jobs we have finished lately, with the postcode and what was involved.
- CF14 April
Powerflush + MagnaClean. 4-bed Whitchurch, 3 cold rads, sorted in a day.
- CF11 April
System balance only, saved the homeowner £400 vs another firm's flush quote.
- CF24 March
Inhibitor refresh + filter on a Roath terrace. Two-hour visit, two upstairs rads recovered.
- CF64 March
Full flush + 3 new TRVs, Penarth detached. System short-cycling resolved.
- CF23 February
Vertical rad swap + balance, Cyncoed semi.
How the job runs
- 01
Diagnostic visit
60–90 minWe look at every radiator, sample system water, take flow + return temps at the boiler. You get a written assessment that distinguishes a real flush case from a balance / filter case.
- 02
Quote
Same dayFixed-price written quote tied to one of three tiers. No upselling, if a balance and a filter fix it, we'll quote that, not a flush.
- 03
Visit + work
½ day to 1 dayBalance is a single visit. Filter + inhibitor is a single visit. Powerflush is a full day with everything reconnected and recommissioned by 5pm.
- 04
Recommission + balance
1 hourSystem refilled, vented, balanced, flow-temp set for the boiler type and house age. Heating tested across every radiator before we leave.
- 05
Aftercare
12 monthsFree return visit if any rad goes cold or pressure keeps dropping in the year after. Free first-year service when bundled with a boiler install.
Common questions
How quickly can you come out for an emergency?
For genuine emergencies (gas leak, no heat in winter, burst pipe) we aim to be on site within 60 minutes anywhere in Cardiff and within 90 minutes for Penarth, Barry, and the Vale. Out of hours, your call goes to a triage line that wakes Nigel for true emergencies.
Do you charge a call-out fee?
No call-out fee for jobs we go on to quote. Diagnostic visits where we don't carry out work are charged at our standard hourly rate, which we'll always tell you about up front.
How does the heat pump grant work?
The Boiler Upgrade Scheme pays toward an air-source heat pump install at one of two rates. If your home currently runs on oil or LPG you get £9,000, an uplift for off-gas-grid homes that runs until 31 March 2027. If you're on mains gas it's £7,500. The voucher is applied for through the installer before the work starts, so you never handle the paperwork or the money. The grant is discounted at the point of sale.
Are you Gas Safe registered?
Yes, every gas engineer who works under PHBLUE is Gas Safe registered. You'll see our registration number on every quote, every invoice, and every Gas Safety Certificate. You can also verify us directly on the Gas Safe Register's public lookup.
What areas do you cover?
Cardiff and the surrounding South Wales region, primarily Cardiff, Penarth, Barry, Caerphilly, Llandough, Roath, Rhiwbina, Whitchurch, and Cowbridge. If you're nearby and we don't cover your postcode yet, drop us a message and we'll see what we can do.
How much does a new bathroom cost in Cardiff?
For a standard 3-piece bathroom (bath, basin, WC) refit including tiling, flooring and second-fix electrics: £6,500–£9,500 fitted, depending on tile choice and whether the layout moves. Wet rooms and en-suites with shower trays start £8,500. We quote fully fixed-price after a survey; supply-only items are at trade plus 10%.
How long does a bathroom installation take?
A straight refit (same layout, same waste positions) is 5–7 working days. Layout changes that need waste pipe reroutes add 2–3 days. We work clean: dust sheets up, daily clean-down, the rest of the house stays liveable.
Do you do tap repairs or just full installs?
Both. Most tap drips are a £20 cartridge, and we charge £90 for the first hour (covers diagnosis and most repairs) and £55 per hour after. If your taps are end-of-life we'll tell you and quote a swap, never the other way round.
What's the difference between a powerflush and a magnetic filter?
A powerflush is a one-time deep clean of the heating system using a high-flow pump and inhibitor, which clears years of magnetite sludge from radiators, boilers and pipework. A magnetic filter (MagnaClean or equivalent) is fitted permanently on the return pipe and traps sludge as it circulates, year on year. Both are needed for a long-lasting modern system. Powerflush £450; magnetic filter retrofit £180 fitted.
My water pressure is low, can you help?
Yes, first we'll find out whether it's coming in low (a problem with the incoming main, your stopcock, or a partially-closed valve), or dropping mid-house (a leak, a cylinder issue, or scale in the pipework). Diagnostic visit is £90 and gets credited if you go on to have the work done.
Are you WaterSafe registered?
Yes: WaterSafe approved plumber scheme. That's the recognised standard for any work that touches the mains supply (stopcocks, incoming mains repairs, unvented cylinders, water softeners). It's also the scheme insurers and conveyancers look for on home reports.
Do you charge a call-out fee?
No, not for any job we go on to quote or carry out. Diagnostic visits where we don't end up doing work are charged at our standard hourly rate (£90 first hour, £55 after) and we'll always tell you that up front.
Are quotes fixed price or estimates?
Fixed-price for everything we can survey: boiler installs, bathrooms, EV chargers, EICRs, central heating refurbs, heat pumps. Variable-rate for diagnostic and repair work, but with hourly rates published on every relevant page so you know before we start.
Can you take a deposit and stage payments?
For jobs over £3,000 we take a 30% deposit at scheduling, 50% on day one, balance on completion. That covers our materials outlay without exposing you. Smaller jobs are paid on completion. We accept bank transfer, card, and Apple/Google Pay; no cash in hand.
Do you offer finance?
Not directly: we're not authorised to broker credit. For boiler installs, Worcester Bosch and Vaillant both run their own finance schemes (0% over 12 months on installs through accredited installers like us). Ask at quote stage and we'll send you the application link.
Do you give written quotes?
Always. Every job over £200 gets a written, itemised, fixed-price quote before any work starts. The quote is yours to keep, valid for 30 days, and the price on it is what you'll pay: line-item breakdown for materials, labour, and any provisional sums.