- Adrian Marsden
- Commercial boiler expert
Your commercial boiler runs all year round to keep hot water running and heated rooms along with ensuring full compliance. But what about caring for the boiler itself? Read our solutions to some of the most common issues.
1: Your boiler’s pilot light keeps going out
A pilot light is a small gas burner that’s permanently alight inside your commercial boiler. If your boiler’s pilot light keeps going out, the issue could be something as simple as a draught blowing out the flame, or a build-up of soot on the gas nozzle.
Alternatively, a broken thermocouple (a safety device) could be stopping the gas supply.
What you can do
Firstly, make sure your other gas appliances are working properly. If they aren’t, you should contact your gas supplier as soon as possible and get the system looked at.
If your gas supply looks OK, then it might be time to upgrade to a new JLA commercial boiler to ensure full compliance.
2. Your commercial boiler is gurgling, whistling or banging
If your boiler is making unusual noises, the most likely cause is air in the system. Low water pressure or a failing pump could also be the cause. Whatever the cause, try not to ignore it: these noises are usually signs of a fault that could become a more serious issue.
What you can do
If your boiler is humming or vibrating, check its settings. If its output temperatures are set too high, for instance, it could be working too hard for long periods of time. It’s also worth making sure that the boiler’s metal case is properly secure or there are screws missing, it’s much more likely to vibrate.
We recommend calling an engineer to ensure a compliant repair of your boiler.
3. Your boiler is leaking
Causes will vary, depending on where the leak or drip is coming from, but a leaking system could mean a broken seal or valve, or is the result of corrosion. Whatever the reason, this isn’t a problem to ignore and the boiler could no longer be compliant.
What you can do
Sadly, some problems are too serious or technical to tackle yourself. If you’re looking at a boiler leak, it’s always safer to call in a Gas Safe-registered engineer – never try to repair a boiler on your own.
4. Low boiler pressure
If your boiler’s pressure gauge shows a reading lower than 1 bar, or consistently loses pressure when it’s been topped up, you could be looking at a system leak or a faulty expansion vessel.
What you can do
Check for obvious leaks on the property – radiators are the best place to start. If you do find a leak, call an engineer to repair your boiler immediately.
If there are no visible leaks, you could re-pressurise the system by carefully following your boiler manufacturer’s instruction manual. But if there’s still no improvement, call an engineer – it’s likely there’s a failed component in the system, or there’s a hidden leak.
5. Your radiators are cold
If your radiators are only partially warm, or only some of them are working, the most likely culprit will be air in the commercial heating system.
What you can do
Carefully bleed your radiators using a radiator key, which you can easily buy if you don’t already have one. Firstly, turn off the heating so hot water isn’t flowing to your radiators.
If there’s no improvement, the system might need flushing – this needs to be carried out by a professional heating engineer.
6. The boiler is kettling
If your boiler is whistling like a kettle, a build-up of sludge, minerals or limescale is probably restricting its water flow, and causing the water inside the boiler to overheat. This is a common problem in areas with hard water.
What you can do
A kettling boiler is usually a sign that bigger problems are just around the corner, so it shouldn’t be ignored. Not only will the boiler be working much harder (and more inefficiently) to reach the temperatures you need, but it could also cause cracks and damage to key components of the boiler.
To solve the issue, call out a registered professional engineer and get your system professionally flushed.
7. Your boiler isn’t responding to the thermostat
A faulty thermostat can sometimes cause problems in a system that’s otherwise healthy.
What you can do
Check your thermostat. Sometimes, something as simple as an accidental knock can switch off or change its settings. If your thermostat settings look normal, but the temperature isn’t – or the controls aren’t responding at all – it could be time for a replacement, especially if it’s an older unit.
As this job involves wiring, it’s vital that you get a qualified professional involved.
8. Your condensate pipe is frozen
Condensing boilers come with a pipe that carries condensate to an external drain. In colder weather, the condensate pipe can sometimes freeze up, causing noise in the pipes. Your boiler should have a fault code that tells you when its condensate pipe is frozen.
What you can do
Thawing a condensate pipe is often as easy as warming up the pipe with a hair dryer or hot water bottle. Start near the boiler and work your way down the pipe – you should see water begin to flow into the drain. We suggest calling out a registered engineer to ensure this has been correctly.
9. Your boiler keeps switching off
This could be caused by a variety of different issues, including a thermostat problem, low water pressure, or a lack of flow.
What you can do
Check the boiler’s pressure and thermostat (see issues 4 and 7 above). If adjusting the thermostat, bleeding your radiators and/or re-pressurising the system doesn’t do the trick, call a registered boiler engineer to repair your boiler.
10. There’s no heating or hot water
Being without heating and hot water is a problem that needs solving fast, particularly for care homes, housing and hospitality sector. In this situation, there could be a number of causes, most of which will need an emergency call-out and replacement parts.
What you can do
There’s rarely one single issue that leads to a boiler failing to provide heat or hot water, but it’s worth checking before anything else that there are no issues with your boiler’s water pressure or thermostat.
If you’ve checked for these issues and still have no heating or hot water, it’s time to call in an engineer.
Keep compliant with JLA's heating service contracts
With JLA’s commercial heating service contracts, we’ll keep your boiler running smoothly, prevent future issues and ensure it is fully compliant.
Our extensive network of Gas Safe-registered commercial boiler engineers are located throughout the UK keeping your heating on and your hot water flowing.
- An annual service and gas safety check
- Asset specific compliance certification (CP15)
- Same/next day business hours response times
- No call out charges
- 24/7 helpline for faults or emergencies
- A choice of 5 or 7 day a week contracts
