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Baxi Boiler Problems: How to Fix the Common Baxi Boiler Faults

Is your Baxi boiler giving you trouble? Then you’re in the right place! This guide will help you troubleshoot the most common Baxi boiler problems.

Before we begin, keep in mind that fixing most Baxi boiler problems requires a Gas Safe registered boiler repair engineer.

Baxi Boiler Problems
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Baxi Boiler No Hot Water, or Other Problems?

If you already know the fault code for your Baxi boiler, click through to the relevant section.

Baxi Boiler No Hot Water

This is one of the most common Baxi boiler problems, but it can also affect any other boiler brand out there.

You turn on a tap or shower, and nothing happens. At best, you’ll notice it only gets lukewarm, and that’s with the heating on.

The problem likely lies with the diverter valve, or a part in the diverter valve such as the diaphragm. In a combi boiler, a diverter valve directs hot water to either the central heating system, or the taps and showers.

We’ve covered diagnosing a faulty diverter valve in detail here.

Fixing Hot Water Problems

After some careful inspection, you might be lucky in that the issue is just the diagram washer. However, the time heating engineers would need to disassemble the boiler and fit new parts means it’s much more economical to replace the whole diverter valve.

Costs for fixing a diverter valve will sit around £250-350. If you’d prefer to invest that cash in a new boiler with a long warranty, you can get a price online here.

Banging Coming from Baxi Boiler

Possible Faults: 128

One of the most common Baxi boiler problems in the HE range is banging noises coming from the boiler. This is not usually a constant banging noise. It tends to happen only when the boiler cycles on and off, or when it’s started for the first time.

It’s hard to pinpoint this as the exact problem without taking off the cover and having a good look, as well as disregarding any other potential issues.

Fixing Banging Noises on a Baxi Boiler

The most common fault relating to banging on the Baxi HE range is a broken burner. The newest burner we have seen break has been 4 years old. When they break sometimes they’ll display a 128 error code.

In general, this is a more typical issue if you’ve got an old Baxi boiler — we’re talking 6 years or older.

The cost of the fix will depend on the exact model. In general, expect to £320-450 including labour to have this replaced.

As with most old boilers. If this is a fault on an old Baxi boiler (5-6 years or older), it’s usually much more economical to replace it. It’s likely there are many other parts coming to the end of their life, and sometimes they simply compound.

Have a Gas Safe registered heating engineer come around and make their assessment before going for a replacement. If a replacement seems like the better choice for you, you’ll find good prices on brand new Worcester boilers here.

Worcester Bosch Greenstar 4000

Baxi Boiler Leaking

Possible Faults: 118, 119, 270

This Baxi boiler fault is common with the Baxi Solo range, the 105HE, and the 133HE Plus — you’ll find a pool of water below the boiler. We’d expect to see 118, 119 or 270 error codes if this is the case.

There are two likely causes of the boiler leaking water:

  1. The pump
  2. The housing for the diverter valve

Although many older boilers last a long time, their parts degrade. Pumps are prone to breaking a seal when they come under excess water pressure (such as a block in the pipework) or they work themselves loose.

On the above models, some internal parts were made of plastic, and years of vibration cause them to crack. This is particularly the case around the diverter valve.

Fixing Leaks on Baxi Boilers

First, the heating engineer will need to isolate the problem. And once it’s isolated, the affected component needs to be replaced.

Baxi do offer a spares kits for pumps and internal housing. But the problem is, no boiler fix is an easy job. The time and money spent on labour means that replacing the whole pump or housing is much more economical.

Make sure the heating engineer takes a good look at the internal parts — leaks can often cause other issues with the boiler’s components.

After leaking on other metal components, it’s very likely there are other parts that have rusted and need to be replaced.

Baxi Boiler Keeps Locking Out

Possible Faults: 110, 160, 166

All boilers are prone to lockouts from time to time, but this is one of the most common Baxi boiler problems affecting the Solo 1PF and 2PF models.

The root of the problem comes from the boiler getting overheated, which causes the boiler to lock out to preserve internal components and further damage.

This is not easy to diagnose without error codes. Asides from leaks, there are other problems that can cause a boiler to lock out including fault codes: 110 (overheating), to 160 (a faulty fan) or even 166 (air pressure switch fault).

Fixing Baxi Lockouts

A common culprit for this fault on Baxi boilers is a lack of pressure. If your system is set lower than 1.5 bar then it won’t operate correctly.

Now, the quick fix is to top up the boiler pressure using the filling loop. And once you’ve topped up the boiler pressure, you’ll need to reset the boiler.

But here lies a problem — the boiler has lost pressure, and that means there is an underlying issue that needs to be fixed. In most cases, the root cause behind boiler pressure loss is a leak somewhere in the system. You can do some visual checks to try and isolate the problem. Check for leaks on:

  1. Radiators
  2. Towel rails
  3. Pipe work
  4. Radiator valves
  5. Beneath the boiler (this could be the pump)
  6. The expansion vessel

Baxi Boiler Won’t Ignite

Possible Faults: E133, 3 red flashes

If you’ve gone through the reset steps above, the issue could be purely ignition-related.

This is a common issue with the 100e and 105e models.

Fixing Ignition Problems

An engineer will need to go through a troubleshooting process to determine what the problem is. A common assumption is that if the ignition leads look old, replacing them will fix the problem.

And it’s a possibility, but that’s not the right route to take before considering all other options.

An engineer will need to check:

  1. Gas supply
  2. Operation of the gas valve
  3. Ignition leads
  4. Combustion chamber and seals

The fix here is usually just replacing the faulty part.

Now, if the ignition leads have failed due to excess debris, ask the Gas Engineer to clean out the system so it doesn’t happen again. This will also ensure that other parts in the system are not exposed to this debris.

How to Reset a Baxi Boiler

Depending on the Baxi model, you’ve got 3 ways to reset a Baxi boiler — with a button, thermostat control knob, and ON/OFF selector switch.

How to Reset a Baxi Boiler With a Reset Button

  1. Press and hold the button until the red lockout light shuts off.
  2. If the lockout reoccurs, consult with a Gas Safe engineer or your boiler cover provider about the next steps.

How to Reset a Baxi Boiler with a Thermostat Control Know

  1. Turn the thermostat knob anticlockwise fully, and hold it there until the red lockout light shuts off.
  2. Return the knob to your preferred temperature setting.
  3. Contact a Gas Safe engineer if the lockout recurs.

How to Reset a Baxi Boiler with an ON/OFF Selector

  1. Turn the selector switch to “R”, and hold it there for 5 seconds.
  2. Release the switch.
  3. If the fault recurs and your boiler locks out again, get a Gas Safe engineer to inspect the appliance.

Baxi Boiler Fault Lights

Some Baxi boiler models, such as the BAXI ECOBLUE, BAXI 600, and others, use flashing lights to display specific faults. These vary depending on the model, but generally signify the following problems:

  • 1 green flash — maximum flow temperature exceeded
  • 3 green flashes — no flame detected during operation
  • 4 green flashes — connection error with PCB, wiring fault
  • 5 green flashes — configuration error, PCB fault, faulty PU
  • 6 green flashes — possible fault in combustion control unit or miscellaneous error
  • 1 red flash — bad connection to flow, temperature fault, flow fault, or sensor fault
  • 2 red flashes — boiler overheating issues, possible PCB fault
  • 3 red flashes — ignition fault
  • 4 red flashes — fan fault
  • 5 red flashes — parameter or PSU fault
  • 6 red flashes — miscellaneous fault

Keep in mind, that if the boiler is experiencing a PCB fault, the flashes you see may not point to the correct problem. Or, there may be nothing else wrong with your boiler, apart from a malfunctioning PCB. To know 100% what’s going on with your boiler, we urge you to call a Gas Safe engineer to investigate any faults.

Old Baxi Boiler Breaking Often? Consider a Replacement

If your old Baxi boiler is breaking often, you may be spending more on repairs in the long run than what you’d pay for a replacement. For example, a faulty PCB alone could set you back over 350 quid, while a new heat exchanger could cost upwards of £500 (you can read more about boiler repair costs here).

So, instead of pampering your old Baxi boiler with new parts while it’s deteriorating, it may be worth considering a replacement. The best way to pay less for boiler replacement is to solicit as many quotes as possible.

To this end, we urge you to contact at least 3 local installers for an estimate. Next, you can use Heatable’s online calculator to get a fixed price on a range of suitable boiler models. All you have to do is fill in an anonymous survey about your property, and you’ll get the prices on your screen in less than 2 minutes.

Since Heatable have fantastic deals with the likes of Worcester and Viessmann, and their overhead is quite low, you’ll find they have excellent boiler models at competitive prices.

Heatable boiler installations

If you choose not to use Heatable, at least you’ll have another quote to compare against what the local installers send you.

Baxi Boiler Problems: What’s Next?

If we haven’t covered the fault you’re experiencing with your Baxi boiler, please submit a comment below and we will reply as soon as we can.

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