Last Updated on 15 July 2025 by Maelle
Looking for tips on repairing and maintaining your boiler? Or wondering if it’s time to replace it? This guide covers common repair and maintenance issues, provides troubleshooting tips, and helps you decide when to call an HVAC professional.
Boiler Shuts Off
If your boiler keeps shutting off, it could be due to insufficient pressure or a blockage in the system that’s restricting water flow.
Should you try to fix it yourself or call an HVAC professional?
You can try repressurizing your boiler yourself. If your boiler pressure is adequate and doesn’t require repressurization, call a heating technician.Troubleshooting Tips
You can repressurize your boiler in several different ways, including using a refill key or adding water and increasing the pressure using refill hoses. The first method involves the following steps:
Turn off the power to your heating system.
- Remove the tray from under your boiler.
- Remove the filling key from the tray.
- Place the filling key in the key ring of the key collector.
- Turn the key to the unlocked position.
- Using a wrench, turn the manifold nut counterclockwise.
- Check the boiler pressure gauge
- and turn the nut when the gauge reaches 1.5 bar. If there is too much pressure, turn the nearest radiator release button.
- Turn the key to the locked position.
- Remove the filling key and place it back in the tray.
- Turn the boiler back on.
- You can also try adding water and increasing the pressure through the filling pipes by following these steps:
Turn off your boiler.
- Check that the fill loop hoses are properly secured.
- Using a screwdriver, open the fill valves.
- Close the fill valves when the pressure gauge reaches 1 bar.
- Restart your boiler.
- General cost of professional repairs: €40 to €60 for a new ignition switch (natural gas boiler); €25 to €50 (propane boiler); €35 to €60 (oil boiler); €60 to €100 (electric boiler). Labor can cost between $60 and $80 per hour.
Frozen Condensate Lines
All boilers have a condensate line that drains acidic water from the boiler. This line is usually connected to an outside drain, but during the winter months, it can freeze. Should you try to fix it yourself or call an HVAC professional?
When your condensation pipes freeze, you can try thawing them yourself or call an HVAC professional. Troubleshooting Tips To thaw them yourself, try pouring hot water over the pipe. You can also try placing a warm cloth or microwave heat pack over the pipe. After thawing the pipe, you may need to reset the boiler. If you feel you can’t perform this task safely, contact an HVAC professional.
General cost of professional repair: $300 to $500.
Boiler Keeps Going Out
If your pilot light keeps going out, a faulty thermocouple may be preventing the gas supply from reaching the boiler. Check for a gas supply problem before attempting to relight the pilot light. Should you try to fix it yourself or call an HVAC professional?
If you feel comfortable relighting the pilot light yourself, be sure to carefully follow the instructions provided below. However, it is strongly recommended that you contact an HVAC professional to help you safely resolve the problem.
Troubleshooting Tips
If you want to try to resolve this problem yourself, follow these steps to ensure your safety:
Check that there is no problem with the gas supply (if not, contact your gas supplier). Follow the instructions in your furnace manual to light the pilot light. If you cannot do it yourself, contact an HVAC professional for help.
General cost of professional repairs: $80-$100
Drips and Leaks The most common cause of dripping and leaking is a ruptured internal component such as a pressure valve or pump seal. To find the cause of your boiler leaking or dripping, you should contact an HVAC professional. Should you try to repair it yourself or call an HVAC professional?
Don’t try to fix this problem yourself. Contact an HVAC professional.
General cost of professional repairs: €35 to €55 per linear foot for labor and materials.
- Low boiler pressure
- A leak in the water system, recently bled radiators, or the need to install a new safety valve can all cause low boiler pressure.
- Should you try to repair it yourself or call an HVAC professional?
You can look for a visible leak in the system, but once you’ve found one, it’s best to call an HVAC professional unless you feel comfortable trying to repressurize the system yourself.
Troubleshooting Tips
Follow the instructions in your heating system manual to ensure your safety. General cost of professional repairs: $200 to $600 for faulty pipes, valves, or a circulator. Radiators Not Heating
When your radiator isn’t heating, there may be a buildup of sludge or air in the system. You may need to bleed the radiator if only the bottom of the radiator is heating. If your radiators aren’t heating, they may need to be balanced.
Should you try to fix it yourself or call an HVAC professional? This problem is fairly easy to resolve and doesn’t require the intervention of an HVAC professional.
Troubleshooting Tips
Adjust the valves on all the radiators in your property to ensure each one is receiving sufficient hot water. To rebalance your radiators, you will need the following items:
Paper and pen
Radiator bleeder key
A radiator valve adjuster (or an adjustable wrench)
A digital thermometer or a multimeter with a thermometer function.
Once you have everything you need, follow these steps:
Turn off the heating system and allow it to cool completely.
Bleed your radiators to remove any air.
Remove the valve covers from the caps and fully open all the valves by turning them counterclockwise. Next, fully open the thermostatic radiator valves. The control valves require a special adjusting device or an adjustable spanner to do this.
Make a list of all the radiators in your house.
Turn the heating back on and note the order in which the radiators start to heat up. This can give you an idea of the order in which the hot water reaches each radiator. Numbering them makes the process a little simpler.
Turn the heating off and wait for it to cool down again.
Turn it back on and go to the first radiator on your list.
- Turn the control valve clockwise until it is closed. Then open it again a quarter turn. Once the radiator is fully heated, measure the temperature of the pipe leading to one of the valves and note it down.
- Then, measure the temperature of the pipe leading to the other radiator valve. Gradually open the control valve until there is a difference of 12 degrees Celsius (or 10 degrees Fahrenheit) between this temperature and the last one you measured.
- Repeat the process for each of your radiators and you should have a balanced system.
- General cost of professional repairs: €190 to €380.
