Boiler 4 April 2023

7 Common Gas Boiler Installation Mistakes to Avoid

Gas Boiler Installation Mistakes You Should Avoid

Installing a gas boiler can be complex, and even small mistakes can lead to major issues down the line. To ensure your installation goes smoothly and your boiler runs efficiently and safely, it’s important to be aware of common installation mistakes and how to avoid them. Here are seven common gas boiler installation mistakes to avoid:

Improper Sizing

A boiler that’s too small won’t heat your home properly on the coldest days. A boiler that’s too large is the more common error, and the more expensive one: it fires up, satisfies the demand almost immediately, shuts down, and repeats that cycle all day. That short-cycling wears out components and burns more gas than a correctly sized unit running steadily.

Poor Ventilation

Every gas appliance needs the right air supply and a flue that terminates somewhere legal — clear of windows, doors and boundaries by the distances the manufacturer specifies. Get this wrong and you risk products of combustion, carbon monoxide among them, finding their way back into the house. It is the single mistake on this list that can hurt someone.

Incorrect Boiler Placement

Position affects more than looks. A boiler tucked somewhere with no service access means every future repair costs more in labour. A long flue or condensate run adds cost and, in the case of the condensate, adds a pipe that can freeze and shut the boiler down in January.

Using the Wrong Materials

Undersized gas pipe is the one we find most often. A new boiler may need more gas than the old one, and if the existing pipe cannot deliver it the boiler will never work properly no matter how good it is. Checking the gas rate and the pipe run is part of a proper survey, not an optional extra.

Not Sealing Connections

A joint that weeps rather than pours is the dangerous kind, because nobody notices it for months. By then it has been quietly soaking a floor. Every joint we make gets tested under pressure before we put anything back.

Ignoring Manufacturer Instructions

It also voids the warranty. Manufacturers are specific about flue lengths, clearances, filters and system cleanliness, and they will decline a claim if the installation did not meet them. Following the instructions is not box-ticking; it is what keeps your cover intact.

Not Hiring a Professional

It is also illegal to do otherwise. Only a Gas Safe registered engineer may work on gas appliances, pipework and flues. Anyone who offers to fit your boiler without showing you a Gas Safe card is telling you something important about how the rest of the job will go.

What We Do to Avoid Them

Most of these mistakes trace back to the same root cause: quoting a job without properly looking at it. A price given over the phone is a guess, and guesses get corrected during the installation — usually at your expense, or by cutting a corner.

So we survey first. We check the gas supply and pipe sizing, work out where the flue can legally terminate, look at the condition of the radiators and pipework, and establish whether the system needs flushing before anything new goes onto it. Only then do we price it, and the price we give you in writing is the price you pay.

How to Check an Installer Before You Commit

You do not need to be technical to sanity-check a quote:

• Ask for the Gas Safe number and check it at gassaferegister.co.uk. Ours is 951167.
• Insist on it in writing. A verbal figure is not a quote, and it will not protect you when the job grows.
• Ask what’s included — specifically whether removal and disposal of the old boiler, a system flush or filter, and the Building Regulations notification are all in the price. Ours are.
• Ask who registers the boiler. We handle the manufacturer registration and the Gas Safe notification for you.
• Compare like with like. A cheaper quote for a lesser boiler with a shorter warranty is not actually a cheaper quote.

Talk to Us

We are Gas Safe registered and cover Tonbridge, Tunbridge Wells and the surrounding Kent villages. Installations are quoted free, in writing, at a fixed price, and our workmanship carries a 12-month guarantee on installations (90 days on repairs). Call 01732 792 454 or see our boiler installation service.