Maintenance
A boiler that keeps losing pressure.
One drop on the gauge, after you have bled a radiator, can be the heating system asking for a top-up the manual already describes. A gauge that falls again, or any smell of gas, is the point where you stop and phone.
Checked 13 October 2026. For homes in Great Britain. The Malta directory does not use this emergency line or Gas Safe.
This note does not inspect the boiler and it does not tell you a bar reading to aim for. The marked range is in the manual for that model. If you are unsure, phone a Gas Safe registered engineer.
Smell of gas comes before the gauge
If you smell gas, or you suspect carbon monoxide, the pressure gauge is not the job. National Gas says to call 0800 111 999, free, 24 hours. Open doors and windows. Do not smoke or strike a match. Do not turn electrical switches on or off. Turn the meter off at the control handle unless the meter is in the cellar, and do not go into a cellar to reach it. Then call.
That call is to the gas emergency service, not to a business on this directory. The rules for who may work on the appliance afterwards are on who is allowed to work on gas in a home.
When the gauge, on its own, is a reason to phone
A sealed heating system loses a little water when radiators are bled. The manual for the boiler shows the range the gauge should sit in when the system is cold. One top-up that stays put can be the end of that story. This page does not walk through the filling loop, because the valve and the safe range differ by model, and overfilling is its own fault.
Phone a Gas Safe registered engineer who is qualified for boilers when any of these are true:
- You have topped the system up and the gauge falls again over the next days.
- You can see water under the boiler, at a valve, or on a pipe, and you cannot say where it is from.
- The boiler locks out, or it will not restart, after the pressure has moved.
- You do not have the manual and you cannot tell what the gauge is asking for.
Keep topping a system up that will not hold water and you are adding water to a leak. That is the moment to stop and have the system checked. HSE says work on the gas boiler itself must be done by a Gas Safe registered engineer. Water pipes and radiators can be a different trade. The final connection to the boiler is gas work.
If the engineer says the boiler should be replaced
A replacement price, and what should be written on the quote, is what sits inside a price for a replacement boiler. A heat pump grant in England and Wales is a different scheme: whether the Boiler Upgrade Scheme is still open.
To find a phone number, open the plumbing and heating list, including London and Manchester. Gas Safe on a card is shown only when that record already has it. You still ask to see the ID card. You phone the business yourself.
Sources
- National Gas, emergency contacts. 0800 111 999. Checked 13 October 2026.
- HSE, domestic gas frequently asked questions.
- HSE, who can do a gas safety check. Wet work and work on the boiler.
Questions on this fault
The boiler pressure is low and I can smell gas. What comes first?
The National Gas Emergency Service on 0800 111 999. National Gas says the line is free and open 24 hours, including for a carbon monoxide emergency. Open doors and windows, avoid flames and electrical switches, and turn the meter off at the control handle unless the meter is in the cellar.
The gauge falls again after I top it up. Who do I phone?
A Gas Safe registered engineer who is qualified for boilers. Repeated loss of pressure is a reason to stop topping the system up and have the heating checked. Work on the boiler is gas work. A listing shows Gas Safe only when the record already has it.