John Answers Your Heating and Boiler Questions

If you notice something’s not working properly at home, take a look at our expert’s guide. John has over 38 years of experience in home heating and boilers, and he’s put together some simple checks you can make before calling out a heating engineer. It could save you quite a bit of time, inconvenience and money.


If there is a solid blue boiler light the boiler is active and waiting for instructions from the control thermostat. If your heating or hot water still aren't coming on, this could mean a system failure rather than boiler problems. Refer to your boiler instruction book for advice. If you still can't get the boiler to work, you should call in a qualified engineer.


Boiler not firing up, or boiler won't ignite. Is the blue pilot light out on the boiler? It could mean there is no power to the boiler. If the boiler is not igniting or not firing up, make sure it has not been switched off accidentally. It's more common than you think when a boiler has stopped working, and worth double-checking the power supply is still switched on at the mains plug, or if the fuse has tripped. The power supply can usually be found by the boiler or in the airing cupboard.

If you use a key meter for your electricity, check there is credit/money on it. It sounds obvious, but if you've run out of credit for electricity (or gas) your boiler will not work.

Make sure the controls are switched on so you can operate the boiler.


If you've had a power cut and now the power is back on, try restarting or re-setting the boiler. For guidance on how to do this, see your boiler instruction manual.


If the fuel supply (in the case of oil or LPG) has run out, or been shut off for a period, try restarting the boiler as shown in the instruction manual.

A power cut can throw all the timers out. These will need to be re-set to make sure your boiler comes on at the times you want.


Check your wall thermostat - if the temperature is set too low the boiler will not come on.

If you think there is a gas leak, turn off or disconnect the gas immediately at the meter or tank, depending on your fuel supply.


What to do if you smell gas:

for mains gas call the 24-hour National Gas Emergency Services on 0800 111 999.

for LPG call your gas supplier.

Open all doors and windows.

Don't light anything or use anything electrical -- including light switches.

Leave the house until you get confirmation that it is safe for you to return.


If InstaGroup changed the radiator we may replace or repair the leak under our a 2-year workmanship guarantee. If it's over 2 years, there will be a charge.


Radiator TRV (Thermostatic Radiator Valve) not working or leaking water? If InstaGroup changed this within a year, we will come out and fix it. If it's over a year we will charge for the repair.


Cloudy water coming from your tap is perfectly safe and nothing to worry about. What's happening is the calcium bicarbonate that naturally exists in the mains water is being heated by the home's hot water system. During heating the calcium bicarbonate creates millions of bubbles, and this can look like cloudy sediment or milky water. If you were to watch the hot water cool down, it would slowly become clear again.


Cloudy or milky water is more noticeable in areas where the water is high in calcium (chalky) or where limescale is noticeable.


If your boiler is leaking water or keeps losing pressure, check the pressure gauge is set at the right level. The boiler instructions can tell you the correct settings.


There could be air in the system. Bleeding the radiators could help, particularly those at the top of a house. If you have a sealed/pressurised system check the pressure gauge when filling.

The thermostat could be at fault.

Re-check: is the boiler connected to the power supply?


Most well-maintained boilers will last between 10-15 years. If your boiler is over 10 years old, there's a good chance it could do with an upgrade. Older boilers are less energy efficient than current models, so it could make financial sense to replace it.


Signs that a boiler needs replacing can include:

It takes longer to heat up

The pilot flame is burning yellow rather than blue

The boiler is unreliable and often needs repairing

A qualified engineer tells you it's getting difficult to source the parts needed for your type of boiler

Your fuel bills are up, yet your home still feels cold

Your boiler is making noises - clunking or whirring


Get reliable hot water and home heating, plus savings too. An efficient new A-rated boiler such as a Worcester Bosch condensing boiler will not only work better than an outdated boiler, it can save you as much as £2101a year.


InstaGroup is an accredited installer for Worcester Bosch boilers and can offer reassuring 7-year manufacturer's guarantees. Every component of your Worcester boiler and Worcester controls are covered for no extra fee - the same cover from a national energy company would cost over £1,000 for the same period2.

Save on boiler repairs and breakdowns. According to the Which? Report 2017, the average repair bill for a boiler out of guarantee is £1943 -- under our Guarantee that's a price you wouldn't have to pay in the event of a breakdown.


Boilers are rated from A to G for fuel economy. G-rated boilers are the least efficient, giving you less heat and hot water for the amount of fuel they use. A-rated boilers are the most energy efficient.


Upgrading to an A-rated boiler makes it more cost-effective to stay warm at home. It will save you money on your energy bills, and it's better for the environment too.


Our assessor will arrive at a timed appointment. We always work to minimise disruption to your day.


You'll get a no-obligation survey of your home and its needs. The assessor will give you a range of options showing how you could upgrade your current home heating system.

The assessor will see if you qualify for any current offers. They can also discuss ways to pay.


The time it takes to install a new boiler can vary. Some jobs are more complex than others, but we'll assess the work before we start and will always confirm a completion time with you.

The cost of installing a new boiler will depend on your home and current heating system. Book a home assessment and you can find out the most suitable and cost-effective solutions for your household's needs.


Trust our fixed price quotation. The costs for our recommended solutions are fixed, so you know exactly what you'll pay if you decide to go ahead.


Boiler guarantees vary according to the manufacturer. As a Worcester Bosch Platinum Approved Installer, InstaGroup can offer customers a 7-year manufacturer's warranty for all Worcester Bosch boiler installations.