Boiler Installation in Liverpool from £1,299 Fully Fitted: With a FREE Gas Safety Certificate

Combi, system or conventional is the first real decision, and hot water usage decides it more often than house size. A combi heats water on demand with no cylinder, which suits one-bathroom properties and frees up space, but it can only serve one hot outlet properly at a time and it depends entirely on incoming mains flow. A system boiler with an unvented cylinder delivers mains-pressure hot water to several outlets at once, which is the right answer for two bathrooms in simultaneous use. A conventional boiler with tanks still makes sense in a minority of properties, usually where mains pressure is poor. We measure flow rate at the tap before recommending, because that number settles the argument.

Output sizing is the most commonly botched part of a replacement. Boilers are frequently swapped for the same kilowatt output as the unit coming off the wall, even where the property has since been insulated, double glazed or extended. Oversizing causes short-cycling: the boiler reaches temperature quickly, shuts down, and repeats, which wears out ignition components and fans and undermines efficiency. We size the heating output to the calculated heat loss and the hot water output to the demand, and where those conflict on a combi we say which one we are prioritising and why.

Flue, condensate and gas supply are where regulations bite. Flue terminations have minimum distances from openings, boundaries and adjacent surfaces, and plume management may be needed where a terminal sits near a window or a neighbouring wall. Condensate must discharge to a suitable drain with adequate fall and adequate pipe size, or run to an internal soil stack: external condensate runs in exposed positions freeze in Merseyside winters and lock the boiler out, so we size and route them accordingly. Gas supply pipework must be capable of delivering the appliance's rated input with acceptable pressure drop; a new higher-output boiler on undersized existing pipework will not commission correctly.

System protection is not optional if you want the warranty to survive. We cleanse the system, dose it with inhibitor, and fit a magnetic filter on the return so debris is captured before it reaches the new heat exchanger. That filter gets emptied at each annual service. Combined with annual servicing, this is precisely the maintenance record manufacturers ask to see when a claim is made, which is why we hand you the documents rather than leaving you to chase them.