Moving your boiler to a better spot

Why people move a boiler

The usual reasons: the boiler hangs in the kitchen where you want cupboards, it sits in a bedroom cupboard where every tick is heard at night, the attic is being converted, or the bathroom is being rebuilt and the boiler is in the way. Sometimes it’s the flue: an old route that doesn’t suit a modern boiler, while a different wall would give a short, simple one.

The best moment is when the boiler is being replaced anyway. The old one comes off the wall regardless, so the extra work is the new position, not the boiler. If yours is only a few years old, ask me first. Moving it can still make sense, but I’d rather say so honestly than move a boiler that’s near the end of its life.

What has to move with it

A wall-hung combi boiler has six things connected to it, and every one of them has to reach the new spot.

• Gas. A new run of gas pipe, sized for the boiler, with a gas tap right at the appliance. The route has to be one I can test and that stays accessible. See gas pipework.
• Heating pipes. The flow and return to the radiators, plus the parts that live next to the boiler: the filling valve, the safety valve and the expansion vessel. Intergas’s manual, for example, wants the safety valve within half a metre of the appliance.
• Hot and cold water. The mains cold feed in, and the hot pipe out to the taps. A long hot-water run means a longer wait at the tap, which is worth weighing up before you pick the attic.
• Flue and air supply. The boiler breathes outside air and blows its flue gases outside. This is the part that decides whether a position is possible at all; more on that below.
• Condensate. A modern boiler produces condensate that drains through a siphon. Intergas connects it to the sewer through an open connection, together with the safety valve’s discharge. No drain nearby means a pump or a different spot.
• Power. Intergas asks for an earthed socket within a metre of the boiler, easy to reach. In a damp room such as a bathroom, the manual wants a fixed connection with a switch instead of a plug.

The room thermostat stays where it is. Its cable has to reach the new boiler position, or you switch to a wireless one. My guide to choosing a thermostat covers the options.

Where a boiler can and can’t go

Every make has its own installation manual, and the position has to satisfy it. The Intergas manual for the Kombi Kompakt, one of the most common boilers I see, gives a good idea of what’s expected:

• A wall that can carry the weight. A light partition wall may pass the boiler’s noise on as a hum.
• A frost-free room, so the condensate drain can’t freeze. That rules out an unheated garage or shed in a cold spell.
• A little free space at the sides for the casing, and ventilation openings at the top and bottom if the boiler goes inside a kitchen cupboard.
• A cupboard that’s tall enough to get the casing off and the siphon out for a service. A boiler nobody can reach doesn’t get maintained.

The flue is what decides it

The flue and air supply are the deciding factor for almost every relocation. A modern boiler uses either two separate pipes or one concentric pipe, and each model has a maximum total length for them. Every bend eats into that budget: in the Intergas manual a 90-degree bend counts as two metres of pipe. Go past the limit and the boiler can’t deliver its full output.

So the question is always: where does the outlet go, and how many metres and bends are between it and the new boiler? A short run straight through the roof or an outside wall is simple. A long route with several bends through a loft can rule a spot out. The outlet position has rules of its own too; the manual refers to the Dutch standard for flues and combustion air, NEN 2757, and I check the spot against it.

Existing flue parts aren’t automatically suitable for a new boiler, so I assess the whole route before pricing it. In an apartment block with a shared flue, the VvE or building manager has to be involved before anything changes. Boiler installation explains how I handle that.

Permits, monuments and the VvE

For an ordinary house, moving a boiler inside the home doesn’t need a permit. A new flue outlet is the part to check. IPLO, the government’s information point for the Omgevingswet, explains that a flue outlet that sticks out less than half a metre counts as a permit-free alteration to a home, provided the load-bearing structure isn’t changed. If in doubt, the municipality decides. The safe route is the Vergunningcheck on the Omgevingsloket before you plan the work.

A monument is different. Whether it’s a rijksmonument, a provincial or a municipal one, the permit-free rules don’t apply. Rijksoverheid says a renovation of a monument usually needs an omgevingsvergunning, applied for through the Omgevingsloket or your municipality; only ordinary maintenance that changes nothing is exempt. In a protected townscape (beschermd stads- of dorpsgezicht), ask the municipality first. Enkhuizen, Hoorn and Medemblik have plenty of both.

In an apartment, the outside wall and the roof usually belong to the building as a whole, so a new outlet through either is something to raise with the VvE before you book anyone.

What it costs

A relocation falls in my complex band: €2,750-€4,500+ incl. BTW. That’s a guide price; the fixed quote follows an assessment of your home, and the plus sign is there because pipe runs vary a lot. What moves the price within the band:

• how far the gas, water and heating pipes have to travel, and whether they can stay on the surface or need chasing into walls;
• a new outlet through the roof or the wall, and making good afterwards;
• whether the old flue and the old boiler position need capping off and tidying;
• access: a loft hatch and a ladder cost time, a fixed stair doesn’t.

A relocation without a new boiler is priced the same way: photos first, then a fixed quote. And because the system is drained for the move, it’s a cheap moment to have tired radiator valves replaced at the same time.

For everything that goes into the price of the boiler itself, read what a new boiler costs. To compare my quote with another, reading a Dutch quote tells you what to check.

How to get a quote

Send me photos on WhatsApp: the boiler as it is now with the pipes around it, the spot where you’d like it, the wall or roof where the flue would come out, and the route in between. Add your postcode, the make and model, and whether there’s a drain near the new position. I’ll come back with questions, then a visit where needed, and a written price before you book. Work on a gas boiler has to be done by a certified company; the CO certificate guide shows how to check that.

If you smell gas, leave the property and call 0800 9009 from outside. If a CO alarm goes off, get everyone outside and call 112.