Rent-Ready Heating: A Glow-worm Checklist for Landlords in 2026
Rental heating has a split personality. One half is legal: gas safety checks, records, maintenance, alarms. The other half is human: tenants who want a warm bathroom, a shower that works and a landlord who answers the phone. A Glow-worm boiler can sit happily in the middle of both, but only if the paperwork and the practical routine line up.
This checklist is for landlords who want fewer surprises in 2026 — not another manual to file away.
Start with the legal spine
In the UK, landlords have a duty to maintain gas appliances and flues in a safe condition, and to arrange an annual gas safety check by a Gas Safe registered engineer. The record — often called a CP12 — needs to be given to existing tenants within 28 days of the check and to new tenants before they move in. Keep copies; the rules on record-keeping and retention are worth checking for your nation, because England, Scotland, Wales and Northern Ireland don’t all sing from the same hymn sheet.
Carbon monoxide alarms are part of the same conversation. Rules differ across the UK, but if there is a fixed combustion appliance in a room, check what your nation requires and fit alarms to the current standard. Test them at the start of a tenancy and tell tenants what to do if the alarm sounds. A gas safety check is not a substitute for a working alarm.
Pick a Glow-worm that suits the property
A rental boiler should be reliable, straightforward to run and supported by an installer network that can get parts. For a small flat with one bathroom, a combi often makes sense. For a house with two bathrooms and several tenants, a system boiler with a cylinder may be the better fit. The right answer depends on demand, space, water pressure and how the property is used — not just on what is cheapest on the day.
Keep controls tenant-friendly. A simple programmer and thermostat that a tenant can understand beats an overcomplicated smart system that nobody has been shown how to use. If you do fit smart controls, leave written instructions and make sure the tenant knows they don’t need to download an app to get heat.
Build a handover pack tenants actually read
Most heating call-outs start with confusion. A tenant can’t find the pressure gauge. Someone has turned the thermostat off at the wall. The boiler is showing a lockout code and nobody has the manual. A one-page laminated card can prevent a lot of that.
Include the boiler model, the thermostat setting you expect, how to top up pressure if the system has a filling loop, what to do if the boiler locks out, who to call for repairs, and the National Gas Emergency Service number for a gas smell. Add the gas safety record and service date. Keep a copy in the property and email one to the tenant.
Servicing protects the warranty and the tenant
Glow-worm warranties usually depend on annual servicing by a Gas Safe registered engineer, and the terms are worth reading before you buy. Book the service before winter rather than waiting for a breakdown. Ask the engineer to check the flue, combustion readings, pressure, condensate route and any magnetic filter. If the property has a system boiler, confirm the inhibitor levels and service the cylinder as needed.
Keep the service record with the installation paperwork. If you change tenants, the next engineer should be able to see what has been done and when. A boiler with a clear history is easier to repair, easier to warranty-claim and easier to sell to a future tenant as a well-maintained home.
Warranty transfer and the paperwork trail
When you buy a rental property with a Glow-worm boiler already fitted, find out whether the guarantee is still live and whether it can be transferred. Check the original installation date, the Benchmark record and any service history. Register the boiler in your name if the scheme allows it, and keep proof of purchase and installation. If you replace the boiler, don’t let the certificate and warranty details disappear into a drawer.
Tenants move; paperwork shouldn’t. Keep digital copies of the gas safety record, service invoices, warranty terms and installer contact details. If a repair is needed, the warranty provider may ask for them.
Plan for repairs before the heating fails
Decide who tenants call first: you, a letting agent, or a repair plan. If you use boiler cover, check what it includes and how quickly it responds in cold weather. Keep the name of a Gas Safe engineer who knows the property. Show the tenant where the boiler isolation valve is and tell them not to attempt gas work themselves.
For a suspected gas leak, the advice is simple: don’t touch electrical switches, open windows, get out and call the National Gas Emergency Service on 0800 111 999. That is not a boiler-repair call.
Brief the installer properly
A good installer will ask questions; a landlord should have answers. Tell them how many people live in the property, how many bathrooms there are, whether the boiler is in a cupboard or loft, where the flue can go, where condensate can drain, and what access arrangements apply. Confirm that the work will be notified under Building Regulations where required, and ask for the Gas Safe number, Benchmark record, compliance certificate and warranty registration.
If the property is tenanted during the install, agree access times and a safe route in advance. A boiler swap is disruptive enough without a surprise over who is home to let the engineer in.
A simple seasonal routine
Before winter, ask the tenant to check the boiler pressure and test the heating. Confirm the annual service is booked. Check the CO alarms. Make sure the condensate pipe is insulated if it runs outside. Keep a note of any faults and fix small issues before they become December emergencies.
Rental heating is never just about a certificate. It’s about a warm home, a tenant who knows what to do and a boiler that has been looked after. Get those three things right and the paperwork becomes much easier to keep current.
