01962 217 917

Mon - Fri, 8:00am - 5:00pm

01962 217 917

Mon – Fri, 8:00am – 5:00pm

0% Finance available



Tareq's Tips #3

If your heating isn't working properly, try our troubleshooting ideas.

Gas boiler troubleshooting

At this time of year, when it comes to heating it’s off/on… on/off… up/down…

…and it quickly becomes apparent if your radiators aren’t getting up to temperature, if there is any air trapped in the system, if you’re not getting enough hot water or if there’s not enough pressure in your boiler. 

In order to ensure you’ll be kept cosy all winter long, you can book a boiler service from Roost Heating.

We can power flush your system to clear any sludge or you could splash out on a brand new heating system. Before that though, there are some things that you can do yourself to refresh and boost your system – and this in itself could be enough to optimise it for the winter period. Carrying out these simple tasks could kickstart your heating, save you money and even reduce your winter heating bills.

We’ve come up with our top troubleshooting tips for getting your winter heating up and running.

If carrying out the DIY boiler troubleshooting tips below doesn’t make any difference and your heating is still a little lacklustre, give us a call and we’ll arrange a service visit. You’ll be confident that whatever isn’t working is well worth professional investigation by our gas safe, certified team – and we’ll have your heating running effectively and efficiently in no time.

1. Re pressurise your boiler

If you have a combi or system boiler, which are both sealed systems, there is likely to be a water pressure gauge on the front. This should be at a setting of around 1 bar whilst the heating is off.

When the boiler is operating, the gauge will usually rise to 1.5 bar or more and when the system cools down again it should return to around 1 bar.

If the gauge has dropped below the 1 bar level, the water pressure will need to be topped up with mains cold water. You will only need to do this if you have a sealed system boiler. 

You’ll need to find the boiler’s filling loop, which is probably at the bottom of the unit (it’s basically a loop of pipe with a valve at each end – like a silver hosepipe, but sometimes it;’s integrated into the underneath of the boiler).

Make sure the boiler is turned OFF and the ends of the hose are attached to the valves.

Open the valves and you should be able to hear water filling up the system.

Watch the pressure indicator on the boiler until it reaches 1 bar, then close the valves and switch the boiler back on.

If your boiler pressure is too high, you can find more information here, or if your boiler pressure is still too low, you can find more information here

For filling Worcester Bosch boilers with an integrated filling loop see the following guide:


2. Reset your boiler

Refer to the boiler’s manual to find the reset button and press and hold it for 10 seconds. After a few minutes, the boiler should start working again.

Attempt it a second time if the initial reset doesn’t work. If it’s still not working give us a call.

3. Bleed your radiators

With the heating turned on, check the radiators to assess which ones aren’t warm.

Once you’ve identified the ones which need attention, turn off the central heating. Once cool, use a radiator key and attach it to the radiator’s valve.

With a cloth in your hand (to catch water once all of the air is out), slowly turn the key anti-clockwise. If you can hear a hissing sound it means that there is air escaping.

Once all of the air has escaped, the valve needs to be closed again. If you have a sealed system you may need to top up the pressure again. You can find more information about bleeding your radiators here

4. Change thermostat batteries

If you have a digital thermostat, flat batteries can cause heating to fail.

Remove the thermostat housing from the wall mount and turn it over to find the battery removal slots. Take out the old batteries and replace them with new ones.

Most thermostats will require 2 X AA or 2 X AAA batteries.

Fix the thermostat housing back onto the wall mount.

It may take a few days for low battery warning sign to disappear from the monitor. 

If you need further advice about your boiler or heating system , or you want to book a boiler service, boiler replacement or emergency repair – just give us a call.