Founder · Engineer
Mark Whitelaw
Gas Safe · 18 yrs experience. Quotes & complex installs.
About
Family plumbers in the valley since 2009.
Mark Whitelaw started Calder Valley Plumbing & Heating from a single van in Halifax. Fifteen years on, it's still family-run — three full-time engineers, one apprentice, every job booked through one phone number.
The founder
Mark Whitelaw
Time-served plumber, Gas Safe registered since 2007. Trained in Leeds, first job at Wickes, started Calder Valley in 2009 after a house move to Halifax.
"I started this firm because I was sick of the way customers got treated. No-shows. Vague quotes. Surprise costs at the end. We do the opposite of all that. If we say we'll be there at nine, we're there at nine. If we quote £2,400, that's what you pay."
— Mark, founder
The team
Three engineers, one apprentice, all in-house.
No subcontractors. No agency staff. When we show up, you get our team — same faces every time.
Senior engineer
Lee Harrison
Gas Safe · 12 yrs experience. Bathroom builds & heating systems.
Engineer
Sarah Crowther
Gas Safe · 6 yrs experience. Service calls, repairs, emergency cover.
Apprentice
Tasha Whitelaw
2nd-year apprentice. Mark's niece. Always learning.
Credentials
Every certification we hold, in plain English.
Gas Safe Registered
Registration 123456. Every engineer on our team holds individual Gas Safe certification — required by UK law for anyone working with gas. Verify us live at gassaferegister.co.uk.
Which? Trusted Trader
Awarded 2024 and renewed 2025 after Which? mystery-shopped three of our jobs and reviewed our customer feedback. Means a real third party has verified we are who we say we are.
Checkatrade Member
98% positive rating across 130+ verified jobs. Every review is from a real customer with a real address — Checkatrade ring them after the work to verify.
£5 million public liability
Full insurance through Hiscox. Means if anything we do damages your property — extremely unlikely but possible on any job — you're covered up to £5 million. Certificate available on request.
CIPHE accredited
Members of the Chartered Institute of Plumbing & Heating Engineering — the industry's professional body. Means we keep up with regulations, training, and best practice every year.
Manufacturer accredited
Worcester Bosch Accredited Installer, Vaillant Advance installer, Ideal Max installer. Lets us offer extended manufacturer warranties (up to 10 years on most boilers).
Our promise
If we say it, we mean it.
Every job comes with a written 2-year workmanship guarantee, on top of the manufacturer warranty. If something we installed fails because of how we installed it, we come back and fix it at no charge. No quibbles. No fine print.
Ready when you are
Let's talk about your job.
Drop us a line, give us a ring, or book a free home visit. Mark usually picks up the phone himself.