Hot & Cold Water, Unvented Cylinders, Legionella, TMV & RPZ Valves
Del Sol has had plumbing at the heart of the business for over five decades.
Our senior managers started in the industry as apprentices, and between them our team has worked on everything from a dripping tap to complex heating and plumbing installations for major national businesses. Today, our Gas Safe registered engineers deliver commercial plumbing services across the North of England — designing, supplying and installing the right solution for your building, on a different scale to domestic work, with the compliance requirements that come with it.
Get it right and you get more than working taps: properly specified systems mean fewer call-outs, hot water that’s reliably there when staff and customers need it, and compliance paperwork that holds up when an insurer or landlord asks for it.
Every unvented hot water cylinder requires an annual hot water cylinder service by engineers, in line with Building Regulations Section G3 — covering installation checks, electrical checks, pressure relief valves and more.
Regular TMV servicing maintains safe, consistent water temperatures and limits Legionella risk. TMVs should be serviced at least once a year to support Legionella compliance.
Complete RPZ valve testing, installation and certification — protecting water supplies from contamination in line with water authority requirements. Site surveys available.
Maintain water circulation within expansion vessels, preventing stagnation and the growth of harmful bacteria — a key part of Legionella compliance. By converting a standard single-connection expansion vessel into a ‘flow-through’ type, these valves ensure continuous water movement — compliant with BS EN 12897:2006 and BS 6700:2009.
Legionella compliance remedial works only
(Del Sol does not carry out the risk assessment itself — see note below)
Gas installation, let-by and tightness testing (UP1A & UP1) and commercial gas, oil & LPG safety inspections
Gas and water pipework installation — press-fit stainless steel, copper, screwed steel, MDPE and plastic pipe
Mechanical plant room services — service, inspection and repair of pumps, controls and valves
In the rare event of a fault, our qualified plumbers respond promptly — resolving issues efficiently with minimal disruption to your operations.
Commercial plumbing covers hot and cold water systems for factories, retail and offices — larger-scale installations, often with bigger washroom and hot water demands, and stricter compliance requirements than a typical domestic job.
At least once a year, to maintain safe, consistent water temperatures and reduce Legionella risk.
A Reduced Pressure Zone valve stops contaminated water flowing back into the mains supply — required wherever a building’s plumbing could pose a backflow risk to the wider water network. If you’re not sure whether your site needs one, our site survey will confirm it.
A full inspection of the cylinder and its safety components — pressure relief valves, expansion vessels, electrical connections and incoming supply — carried out annually in line with Building Regulations Section G3.
Del Sol has covered all our mechanical, plumbing and heating systems. They keep all various systems up and running and produce all the compliance documents efficiently and keep them up to date. An excellent company who has the customer at heart.
Gulam Murtaza, Head of Facilities, Camira Fabrics Ltd
