Ideal Boiler NO CH Fault Code
The Ideal fault code NO CH no central heating operation Q & A or require an engineer for an emergency boiler repair.
The Ideal Boiler Fault Code NO CH Error Common Q & A
Just below, we have a list of common questions relating to the NO CH fault code on the Ideal boiler.
- What does the NO CH fault code mean on my Ideal boiler?
- If my boiler shows the NO CH fault code, is it dangerous?
- What causes the NO CH fault code to be displayed on my Ideal boiler?
- If the wiring is causing the fault, how will my boiler engineer know?
- Why would the wiring to the PCB suddenly cause a problem?
- How would water damage find its way onto wires and cause damage?
- Why would my heat exchanger be leaking?
- Do I need to replace the heat exchanger if it’s cracked?
- Why would my pump be leaking?
- Do I need to replace my pump if it’s leaking?
- How can boiler vibrations contribute to wiring faults?
- How would the radiator valves contribute to the NO CH fault code being displayed?
- Some of my radiators work, is this a balancing issue?
- What is the diverter valve on my boiler?
- How would the diverter valve cause an issue that leads to the NO CH fault code being displayed?
- Should I replace my diverter valve if it’s sticking, or working intermittently?
What does the NO CH fault code mean on my Ideal boiler
If your boiler is showing the NO CH fault code on the display panel, it means the boiler isn’t recognising the correct operation of the central heating from the boiler. So, this fault code will be displayed when the hot water function is working, but the central heating isn’t.
If my boiler shows the NO CH fault code, is it dangerous
Typically, a boiler that shows the NO CH fault code isn’t dangerous. When a boiler is dangerous, it will lock out. Generally, this happens with faults whereby the gas supply is too high/too low, which isn’t the case here.
If your boiler does lock out though, you shouldn’t keep resetting it. Resetting a boiler doesn’t fix the problem. You’ll need to call an emergency Gas Safe engineer to come and fault find the problem. It’s only Gas Safe boiler engineers that are legally allowed to work on gas boilers.
They’ll reset the boiler, when they’ve fixed the fault causing the NO CH fault code to be displayed.
What causes the NO CH fault code to be displayed on my Ideal boiler
There are several potential causes of the NO CH fault code being displayed on your Ideal boiler.
- Issue with heating controls and/or electrical supply
- Wiring from heating controls to the boiler’s printed circuit board (PCB)
- Radiator valves closed, or blocked
- Diverter valve fault
If the wiring is causing the fault, how will my boiler engineer know
They’ll start with the basics first; all timers and thermostats need to be on for central heating, not just for hot water.
If they are, the boiler engineer will need to check the electricity supply to these heating controls. Using a multi-meter, they can test each component individually. Typically, we find that this is a heating control fault, rather than an actual boiler fault.
If all heating controls are getting power, the engineer will need to check they’re synced correctly with your boiler. If they’re not synced correctly, they’ll be giving and receiving the wrong signals.
This is frequent problem, especially with controls that use radio frequency. On some occasions, we’ve even found that these devices are being controlled by a neighbour’s heating controls, running on the same frequency. So, your boiler engineer will re-sync the heating controls and move them to a different radio frequency if needed.
Why would the wiring to the PCB suddenly cause a problem
When the heating controls on your Ideal boiler aren’t wired securely, they’ll start to work intermittently. If this fault has developed over time, rather than being an issue since you’ve owned the boiler, it’s likely that either water or internal boiler vibrations have caused the problem.
How would water damage find its way onto wires and cause damage
Your boiler works on a sealed system, so water shouldn’t be present. However, parts in boilers do fail. And when some parts fail, they’ll start to leak. The most common boiler parts that contribute to water damage are the heating exchanger and the pump.
Why would my heat exchanger be leaking
Water passes through the heat exchanger when you use hot water or central heating. As it does, small mineral deposits (limescale) from the water can deposit themselves on the heat exchanger. Where they do, the heat exchanger burns too hot, and this can cause hairline fractures or cracks.
As the cracks develop, water starts to leak. And this slowly works its way into (and damages) internal boiler components, wiring and connections. In this case, it’s caused damage to wiring to the heating controls, and the PCB.
Do I need to replace the heat exchanger if it’s cracked
If your heat exchanger is leaking via a crack, it needs to be replaced. The replacement will usually take a full working day and cost upwards of £400.
Why would my pump be leaking
If it’s the pump rather than the heat exchanger that’s leaking, it’s likely the pump’s seals have failed. When they do, a leak will occur. Like the heat exchanger leak, this can damage boiler connections and wiring.
Do I need to replace my pump if it’s leaking
Many quality pump manufacturers have servicing kits on offer. So, your pump could be fixed for as little as £100. However, if your pump is old, it’s likely the seals, bearings and shaft are excessively worn. In this case, it would make sense to replace the old unit with a brand new one.
This is likely to cost around £250 if you use a reliable pump from a quality brand, such as Grundfos.
How can boiler vibrations contribute to wiring faults
If the fault lies with connections and wiring, but it’s not due to water damage, it’s likely to be boiler vibrations. Boilers will vibrate a little. And, these vibrations can lead to connections and wires coming loose over time.
But, if you’ve got another problem (a fan with partially seized bearings, for instance), this could lead to excessive boiler vibrations.
If you’ve noticed your boiler being noisier than usual, make sure you inform your engineer. They’ll be able to re-secure wiring and address the problem that’s causing the excess boiler vibrations, so these connections don’t come loose again.
How would the radiator valves contribute to the NO CH fault code being displayed
If the radiator valves are closed or blocked, this will stop the central heating from working.
The valve might look like it’s open, even when it’s not. When you remove radiator valve’s heads, you expose an adjuster that allows you to balance the heating system. This ensures that water flow is stable throughout the heating system, creating more even heat distribution.
If your radiators haven’t been balanced and these adjusters are closed, your heating won’t work; even if you have all the radiator TRV heads completely open.
The fix here is to get a heating engineer to come and correctly balance your radiators.
Some of my radiators work, is this a balancing issue
If the NO CH fault code is displayed but some of the radiators work, this could be a balancing issue. However, if your heating is correctly balanced, there’s a chance that some of the radiators and radiator valves have been blocked by heating sludge.
Heating sludge is a build-up of iron oxide (rust). This breaks off from the inside of towel rails, radiators and pipework. Generally, this gets broken down into thick and dirty water.
That’s not particularly good for your boiler, but it’s the large chunks of rust that are most harmful.
These large chunks of rust can get stuck in every part of your heating system. If they were to get stuck in boiler parts, the repair costs could be £250 or more.
Likewise, they can get stuck in radiators and valves. If the sludge build-up is extensive, this is going to lead to intermittent heating operation, and the NO CH fault code being displayed.
Your boiler engineer will be able to remove and inspect the radiators and valves that are the potential culprits. If they find blocked valves, they’ll suggest replacing them to trying and clear the NO CH fault code on your Ideal boiler.
What is the diverter valve on my boiler
The diverter valve is the component in your boiler that directs hot water where you've requested it. So, when you turn on a tap or shower, the diverter valve moves into a "hot water" position. When you turn on your heating, it will move to "central heating".
Diverter valves prioritise hot water. So, if you turn on your heating and have a shower at the same time, the shower should stay warm. If your boiler isn’t particularly powerful, there’s a good chance that you’ll find heating temperature drops a little, and that radiators cool down for the duration you use hot water.
How would the diverter valve cause an issue that leads to the NO CH fault code being displayed
Diverter valves are moving components. And, like any moving components, they can wear out and get stuck. If they do get stuck, they’ll not be able to switch between hot water and central heating. So, even though the boiler receives a signal to say you’re demanding central heating, it may not be able to flick over to that setting.
Whilst it’s likely that the diverter valve can be freed, this is going to be a short-term fix. Once moving components like this wear out, they work intermittently. So, it’s unlikely that it will function for long, before another quick fix is needed, to free the valve.
Should I replace my diverter valve if it’s sticking, or working intermittently
If your boiler engineer recognises that the fault is an old, worn and sticking diverter valve, it’s likely that they’ll suggest a replacement. And typically, you should expect to pay around £350 (the exact price will depend on the boiler you have).
With boiler repairs that are this expensive, it’s worth consulting your engineer. Have them assess your boiler and check that all other expensive parts are in good condition. If it’s likely costly parts such as the heat exchanger, pump, PCB and gas valve are also likely to fail soon, a replacement boiler might be a better option.
Other Ideal boiler issues
For more boiler issues regarding the Idea Boiler then please visit the Ideal Boiler Problems And Cures page.