Frequently Asked Questions
At Brennan & Son we try to answer as many questions as possible so that your heating and hot water systems works for you. In the case of minor faults we can often talk to you on the phone about what to do and of course send round one of our engineers if needed. Here are a few frequently asked plumbing questions.
Why do I have no hot water?
There may be several reasons but here are a few common problems
You have a combination boiler and the pressure is low
If the pressure on your combination boiler is less than 0.8 bar the boiler will usually cease to work. This is easily remedied by adding more water into the heating system via the filling loop. Be sure to only fill the boiler to 1.2 bar or thereabouts. If you fill the boiler to 3 bar it will cause the pressure relief valve to activate and the water will pour outside. If you are unable to top the pressure yourself or if it keeps dropping, please contact us.
There may be a fault code on the boiler
Common fault codes and how you can help:
Vaillant F22 or F75, Baxi E119
Low pressure water – use the filling loop to put a bit more water in the central heating system.
This link will help top up the pressure on your Baxi
Vaillant F28, Baxi E133,
Failure during start up, ignition unsuccessful – Check the gas is working & money on the meter. Also check the drain near your boiler to make sure it isn’t blocked. The waste water from the boiler might not be able to run freely. Are the pipes frozen outside?
For other faults, give the office a call.
Your hot water tank hasn’t had enough time to reheat
If you have used more hot water than normal, (perhaps because you’ve had overnight guests), then your hot water may have simply run out. Wait a couple of hours and try it again. If it’s still cold then you may have a more serious problem.
Your hot water tank may not be big enough
If your hot water runs out a lot then you may find that your tank may not be big enough or your water heater powerful enough for your needs. Call Brennan & Son to ask to check if your tank is right for your home and the options available.
The pilot light has gone out
If your hot water has failed because the pilot light has gone out you may wish to relight it. First switch the control to off, wait for a few minutes and then set it to pilot. Use a long lighter and ignite it next to the pilot burner. Many systems have a self-ignite function so all you need to do is hold the button down for a minute and then turn the control on. If you are in any doubt, contact us.
Tripped breaker
If your water heater is electric, the system may have tripped-out. Look in the breaker box and switch on any which are not in line. If none of the above works, then you may have a more serious problem so please contact us so we can get your system working again as soon as possible.
Why is my heating noisy?
Heating systems which hum, gurgle, tap or clang are not only annoying but also a sign they’re not working properly. Banging noises can be caused by poorly-fitted pipes, sludge or TRV’s which have come loose. It can also be caused by low pressure. When the boiler is making a loud noise it could be a problem with the fan or pump.
Why does the pressure on my boiler keep dropping?
If the pressure on your boiler drops once per year it is nothing to worry about but if your pressure drops every month it may be a leak from the radiators and pipework. Looking for green pipes or using a piece of tissue will help you to find leaks that you might not have noticed before. If the pressure is dropping every day then it might be pouring out of the pressure relief valve on the boiler, in this case give us a call.
My radiators are cold at the top?
If the radiators are cold at the top but warm just below it is likely they need a bit more water in them. Venting the radiator with a radiator key will release the air and fill the radiator but remember to top the pressure up on the boiler afterwards.
My radiators are cold at the bottom?
If the radiators are cold at the bottom it is a sign of a heavy sludge build up and powerflushing will be beneficial.
Why does the heating come on with the hot water?
This is usually caused by a faulty diverter valve, although in some circumstances it can be caused by incorrect wiring or an incorrectly piped system.
Why does my heating need a powerflush?
Powerflushing is the method used to clean a central heating system and ensure it runs efficiently. Using specialist equipment, a powerful flow of clean water is pumped through the heating circuit to remove debris such as limescale and corroded materials from the system.
At Brennan and Son we will always carry out a powerflush. This will prolong the life of your heating system by preventing the build up of sludge, guarding against corrosion and preventing wear on pumps and valves. It reduces boiler noise, prevents the need for frequent radiator bleeding and above all will make your heating more efficient, saving you money on your fuel bills.
Useful links:
How to use the Worcester Greenstar Comfort Controls Range:
How to repressurise a Worcester boiler with an internal filling key:
How to repressurise a heating system with an external filling loop.