Like-for-like swap
Quoted
Replace existing rad with new equivalent
- Drain that section of the system
- New rad (Stelrad / Mhs / Quinn) fitted
- New TRV + lockshield
- Refill, vent, balance
- Sentinel X100 top-up
Plumbing
Radiators
Radiator replacement, upgrades, additional radiators, vertical and designer radiators, all fitted and balanced properly so every room reaches temperature at the same time.
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.
Additional radiator
Quoted
Add a new rad to the existing circuit
- Pipework run from nearest available tee
- 15mm copper soldered joints
- TRV + lockshield + air vent
- System balanced after install
- Inhibitor refresh included
Vertical / designer
Quoted
Stelrad Vita, Bisque, Reina or designer rad
- Designer model fitted
- Wall-bracket reinforced where needed
- Bleed-screw discreet placement
- System balanced
- Customer-supplied or trade-sourced
Radiators
Cold rad, lukewarm room, or upgrading style?
Radiator replacement, upgrades, additional radiators, vertical and designer radiators, all fitted and balanced properly so every room reaches temperature at the same time.
At a glance
Quick facts before you read on.
What's included
5 things, no extras on the day- Drain that section of the system
- New rad (Stelrad / Mhs / Quinn) fitted
- New TRV + lockshield
- Refill, vent, balance
How we quote
Confirmed before work startsLike-for-like swap including system drain.
Certification
Gas Safe RegisteredJob done to standards. Paperwork on the day.
Service area
Cardiff, Penarth, Barry, CaerphillyRadiators that are cold at the bottom usually have sludge in them. Radiators that are cold at the top usually have air. Radiators that are warm but the room never quite heats up usually need to be a size larger. We diagnose properly, then fix.
Replacement & additional radiators
A like-for-like swap of an existing rad (including draining that section of the system, fitting the new unit, refitting valves and rebalancing) is £180–£240 depending on size. Adding a new radiator to an existing circuit (running new pipework from the nearest tee, fitting TRV/lockshield, balancing) is £280–£420 fitted.
Vertical and designer radiators (Stelrad Vita, Bisque, Reina, MHS Designer Rads) typically £450–£900 fitted depending on the model. Whether customer-supplied or trade-sourced, we’ll match price either way.
Sizing: the bit most installers skip
Radiator sizing isn’t guesswork. Each room has a heat-loss number based on its volume, exposure, insulation and window area. The radiator output (in BTUs or watts) needs to match that or exceed it slightly.
When we quote a rad upgrade, we calculate the required output for the room and compare against the existing rad. Usually we find one of three things:
- The existing rad is right-sized but underperforming: sludge, air, or balance drift. Powerflush or balance fixes it.
- The existing rad is undersized for the room. A double-panel of the same width gives 60–80% more output. A larger rad costs the same to install, so wrong-sizing is just lazy specification.
- The existing rad is over-sized. Rare but it happens; means the boiler short-cycles. Smaller rad and a TRV solves it.
For heat-pump conversions, every radiator gets re-modelled at survey because heat pumps run at lower flow temperatures (35–55°C versus 60–75°C for a gas boiler) and many existing rads aren’t sized for that. See the heat pumps page for the full radiator re-sizing process.
Balancing
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 any radiator install or powerflush.
TRVs
Replacement thermostatic radiator valves are a 30-minute fix per radiator. £55 per valve fitted for standard mechanical TRVs. Smart TRVs (Drayton Wiser, Tado, Hive Radiator Valve) £80–£110 each fitted plus the cost of the hub.
If you’ve fitted a smart thermostat already (Hive, Tado, Nest, Wiser), upgrading TRVs to the matching brand is the next-most-impactful efficiency upgrade. Per-room scheduling typically cuts gas bills 8–15%.
Common mistakes other firms make
- Replacing without sizing. Swapping a single for a double on a wall-of-windows lounge fixes the cold-room complaint, where a like-for-like would have left it cold.
- Skipping the inhibitor top-up. Every radiator install drains a bit of inhibitor. If it’s not topped up, your protective concentration drops and the next sludge build-up is on the way.
- Not balancing after. A new rad on an unbalanced system inherits the unbalance. We always re-balance after.
- Air vents in awkward spots. On vertical rads especially, bleed-screw placement matters, or every annual bleed needs the rad pulled. We choose the position carefully.
Workmanship and warranty
12-month workmanship warranty on every install. Manufacturer warranties on radiators are typically 5 years (Stelrad, Quinn) or 10 years (MHS, Bisque). Every rad fitted is registered with you copied in.
★★★★★
Installed two radiators for me for a very reasonable price. He did an excellent job and is definitely experienced and knowledgeable.
Recent jobs near you
A few of the jobs we have finished lately, with the postcode and what was involved.
- CF83 April
Caerphilly semi, single → double panel swap + system balance.
- CF14 April
Whitchurch: additional rad in cold conservatory, 8m run from existing.
- CF11 March
Pontcanna terrace, Bisque designer vertical rad in hallway.
- CF24 March
Roath: 3 TRV swaps + system balance.
- CF64 February
Penarth detached, full set of TRVs replaced with Drayton Wisers.
How the job runs
- 01
Photo + measurements
1 minSend photos of the existing radiator, the valves, and the wall measurement. We'll quote a like-for-like or upgrade band before coming out.
- 02
Visit
1–3 hours per radLike-for-like swaps are done in 1–2 hours. Additional radiators or vertical designer rads are 2–4 hours depending on pipework run.
- 03
Drain + fit
Within visitJust the affected section drained, not the whole system. Heat back on inside the working day.
- 04
Vent + balance
30 minSystem refilled, every air vent checked, lockshields balanced so all rads heat evenly. Inhibitor refreshed to spec.
- 05
Aftercare
12 monthsFree return visit if a rad goes cold or the balance drifts. Includes one bleed call-out free for the year after fit.
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.