Boiler playing up?
Start here.
No heating, no hot water, low pressure, a fault code or a radiator that just won't get warm? Tell us what's happening and we'll help you work through the sensible checks first.
Smell gas or concerned about carbon monoxide?
Don't continue with the boiler checker. Move away from the suspected source and follow the National Gas Emergency Service advice.
0800 111 999
Just tell us what's happening.
You don't need to know what's wrong with the boiler. Describe the problem normally and Ask Heat will point you towards the most useful check, answer or next step.
Try things like “my pressure keeps dropping”, “I've got heating but no hot water”, “what does EA227 mean?” or “my radiator is cold at the bottom”.
Ask Heat covers sensible homeowner checks. It won't talk you through opening, servicing or repairing a gas appliance.
Tell me what's happening in your own words.
Let's narrow it down.
Pick the closest description. We'll only suggest simple checks you can make without opening the boiler.
What's actually going on?
Similar symptoms can have very different causes. These are useful starting points — not guesses at which internal component has failed.
No heating
Check that the boiler has power, the controls are asking for heat and the system pressure isn't obviously low.
No hot water
Whether the heating still works is useful information. Heating but no hot water is different from losing both.
Low pressure
Many sealed heating systems operate at roughly 1–1.5 bar when cool. Use the instructions for your particular boiler before repressurising.
Pressure keeps dropping
Repeatedly topping the system back up isn't the same as fixing why it's losing pressure.
Fault code
Write the code down. It tells us what condition the boiler has detected but doesn't necessarily identify the failed component.
Cold radiators
One cold radiator doesn't automatically mean the boiler has failed. Air, valves, balance and circulation can all affect radiators.
Low pressure shouldn't become a routine.
For many sealed domestic heating systems, around 1–1.5 bar when cool is a normal sort of range. The correct pressure for your boiler should always be checked against its user instructions.
If your boiler needs repressurising, the important thing is knowing which filling arrangement you have. Worcester boilers don't all fill in the same way.
Your system may need repressurising using the correct procedure for your boiler.
Repeated pressure loss needs investigating rather than continual topping-up.
Some increase is normal. A large or repeated increase should be checked.
Don't guess which valves to turn. Ask Heat or book an engineer.
Which filling system do you have?
Choose the one that looks like yours. These are Worcester Bosch homeowner videos.
Keyless filling link
Used on a number of newer Worcester installations. If this looks like your filling arrangement, watch Worcester's guide.
Official Worcester Bosch homeowner guidance.
Internal filling link / key
Many older Worcester installations use an internal filling arrangement rather than the newer keyless system.
Official Worcester Bosch homeowner guidance.
Neither looks like yours?
Your system may use an external filling loop or another arrangement.
Don't start turning valves if you're unsure.
Sometimes it's easier to see it.
These are for sensible homeowner checks only — not opening, servicing or repairing a gas appliance.
Resetting your Worcester boiler
A normal reset can clear some one-off lockouts. If the same fault returns, don't keep resetting it.
Official Worcester Bosch homeowner guidance. If the same fault returns, book a repair.
How to bleed a radiator
If a radiator is cold at the top, trapped air is one possible cause. Worcester shows the normal homeowner procedure.
Official Worcester Bosch homeowner guidance. Check your heating system pressure afterwards.
Your boiler is trying to tell you something.
A fault code is useful diagnostic information, but it isn't a parts list. The same displayed condition can have more than one possible cause.
Make a note of the complete code and your boiler model if you know it. That can be useful when you book a repair.
This relates to the boiler failing to detect a flame following an ignition attempt. The code doesn't by itself identify which component is responsible.
If your boiler's user instructions specify a normal homeowner reset for the displayed fault, one reset may be appropriate. If the fault returns, book a repair.
Take a photo of the display. Don't start changing service settings or opening the appliance.
A cold radiator doesn't always mean a broken boiler.
Cold at the top
Trapped air can be one possible reason. If you bleed the radiator, check the boiler pressure afterwards.
Cold at the bottom
Restricted circulation or deposits can be possible causes. It doesn't automatically mean you need a powerflush.
One radiator cold
If everything else heats normally, the issue may be local to that radiator, its valves or system balance.
Several radiators cold
Check whether the boiler is running for heating and whether the controls and pressure appear normal.
Slow to warm up
System balance, water temperature, controls and circulation can all affect how quickly rooms warm.
Do I need a powerflush?
Not automatically. Heat can assess the symptoms and condition before recommending system cleaning.
Book the right appointment.
A routine boiler service and fault diagnosis aren't the same thing. If the boiler isn't working correctly, book a repair.
Annual boiler service
£70For a boiler that's operating normally and is due its routine annual service.
Book £70 boiler service →Boiler repair
Got a fault?No heating, no hot water, leaks, pressure problems, lockouts, strange noises or another fault? Book a repair rather than a routine service.
Book boiler repair →Not every old boiler needs replacing.
Whether repair or replacement makes more sense depends on the boiler's condition, reliability, age, the repair required and what you want from the heating system longer term.
If repair makes sense, repair it. If you're already facing repeated faults or a significant repair, it's reasonable to compare that with replacement.
Why isn't my boiler working?
Start with the basics: does the boiler have power, are the controls asking for heat, does the pressure look normal and is a fault code displayed? If those checks don't reveal something straightforward, book a repair.
Why do I have no heating?
Check the heating programme, thermostat setting, boiler power and system pressure. If the controls are requesting heat but the boiler doesn't respond correctly, it needs further investigation.
Why do I have heating but no hot water?
That's useful diagnostic information. The next checks depend on whether you have a combi boiler or stored hot water. If you book a repair, tell us the heating still works but the hot water doesn't.
Why do I have no heating or hot water?
Check boiler power, pressure, controls and any displayed fault code. If the boiler has locked out, use only the normal reset procedure in its user instructions. If the fault returns, arrange a repair.
Why does my boiler keep locking out?
Lockout is the boiler responding to a condition it has detected. Make a note of the fault code. If the same problem returns after a normal permitted reset, repeatedly resetting it isn't a repair.
Why is my boiler making a strange noise?
Banging, whistling, gurgling, humming and vibration can have several causes. Note what it sounds like and when it occurs. The noise alone isn't enough to safely identify an internal component.
Why is my boiler leaking?
Water can escape from different parts of the boiler or heating system. Don't remove the boiler casing to trace the source. Arrange an inspection, particularly if pressure is also falling.
Should I reset my boiler?
A normal reset may be appropriate for certain lockouts if your boiler's user instructions tell you to do so. If the same fault returns, arrange a repair rather than continually resetting it.
What pressure should my boiler be?
Many sealed domestic heating systems are normally around 1–1.5 bar when cool. Check the user instructions for your particular boiler for its correct operating range.
Why does my boiler pressure keep dropping?
Persistent pressure loss can indicate water escaping somewhere in the heating system or another issue requiring investigation. Repeatedly topping the pressure back up isn't a long-term repair.
How often should I need to top up the pressure?
An occasional adjustment can be necessary. If repressurising has become something you're doing regularly, have the system checked.
Why does pressure rise when the heating comes on?
Water expands as it heats, so some change is normal. A large or repeated increase should be investigated.
Can I repressurise my own boiler?
Many boilers have a homeowner filling arrangement, but the method varies. Follow the manufacturer's instructions for your exact boiler and filling system. If you're unsure which controls to use, don't guess.
Why is one radiator cold?
If the rest of the heating works normally, the issue may be local to that radiator, its valves or system balance rather than the boiler.
Why is my radiator cold at the top?
Trapped air is one possible cause. If you bleed the radiator, check the heating-system pressure afterwards.
Why is my radiator cold at the bottom?
Restricted circulation or deposits are possible causes. It doesn't automatically mean the system needs a powerflush.
Do I need a powerflush?
Not every cold radiator or circulation problem requires powerflushing. Heat can assess the condition and symptoms before recommending cleaning.
Can you powerflush microbore heating?
Microbore systems can often be cleaned, but the approach needs to suit the particular system and pipework rather than treating every installation identically.
How much is a boiler service?
Heat Leicester's standard annual gas boiler service is £70 and can be booked online.
How often should my boiler be serviced?
Generally once a year. Regular servicing provides a routine check of the boiler's operation and condition and may also be required under manufacturer guarantee terms.
Is a boiler service the same as a repair?
No. A routine service is intended for a boiler that's operating normally. If you have no heating, no hot water, a leak, pressure loss, lockout or another fault, book a repair.
Can Heat repair a boiler you didn't install?
Yes. You don't need to have bought your boiler from Heat for us to attend a boiler or heating fault.
Do you repair Worcester Bosch boilers?
Yes. Heat Leicester is Worcester Bosch Accredited and works extensively with Worcester Bosch boilers and heating systems.
How much does a boiler repair cost?
The total cost depends on the fault and any parts required. Book a repair so the fault can be properly diagnosed rather than trying to assign one price to every possible boiler problem.
Should I repair or replace my boiler?
Consider its condition, age, reliability, the repair required and whether replacement solves a genuine longer-term problem. An older boiler doesn't automatically need replacing.
How much is a new boiler?
Use Heat's online boiler quotation to get a price based on your home and heating requirements.
Which boilers does Heat install?
Heat Leicester specialises in Worcester Bosch boiler installations and is a Worcester Bosch Accredited business.
How long is the boiler guarantee?
The manufacturer guarantee depends on the boiler and installation package selected. Eligible Heat installations can include Worcester Bosch guarantees of up to 12 years.
Can Heat look after my boiler afterwards?
Yes. Heat provides annual servicing and HeatCare options, so the same local company can continue looking after the heating system after installation.
Can I remove the boiler casing myself?
Don't attempt gas-appliance repairs yourself. Internal boiler diagnosis, servicing and gas work should be carried out by an appropriately qualified Gas Safe registered engineer.
What should I do if I smell gas?
Stop troubleshooting the boiler. Follow the National Gas Emergency Service advice and call 0800 111 999.
What if my carbon monoxide alarm sounds?
Treat a suspected carbon monoxide incident seriously. Move away from the suspected source, follow your alarm/emergency guidance and call the National Gas Emergency Service on 0800 111 999.
That's what we're here for.
If you've worked through the simple checks and your boiler still isn't behaving, book a Heat engineer. Tell us what you've already checked and we'll take it from there.
Thinking it may be time for a new boiler?
Get an online Worcester Bosch installation price without waiting for someone to visit.
Get my boiler price →