What should you if your thermostat isn't communicating with your boiler? Here we explain common causes and solutions.
Are you finding that your boiler is not responding to your thermostat or vice versa?
While a modern, efficient boiler and an advanced thermostat can be a match made in heating heaven, the benefits of such a combination can be lost abruptly if your boiler thermostat stops working as it should.
But why might this happen and what can you do about it?
In this guide, we’ll answer these questions and explore a few related topics to thermostat and boiler functionality.
Let’s begin!
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Thermostat on Boiler Not Working Causes
Note: While the advice provided below should help you diagnose the problem, you should also have a look at the manufacturer’s instructions.
After all, the exact cause and nature of issues that can arise with a thermostat and its connectivity with a boiler can vary from model to model.
As with the vast majority of boiler and thermostat problems, the exact reason your boiler thermostat isn’t working as it should and why your thermostat and boiler aren’t communicating have a range of potential explanations.
Please be aware that if a potential fix is not DIY-friendly or you have exhausted all potential DIY-friendly solutions, you must hire a qualified professional.
Without further ado, let’s explore some of the most likely reasons for these issues and what you can do about them!
Thermostat and Boiler Are Turned Off
DIY-friendly fixes? Yes
You may be tempted to laugh at this suggestion but it’s not too uncommon for the solution to a problem to seem too obvious to consider.
Remember when you couldn’t find your keys and they were in the jacket you were wearing?
We don’t know if there’s an exact word for that phenomenon but we’ve all experienced it!
For instance, you may happen to find that there is a fault code present on your boiler.
If this is the case, turn to the manufacturer’s instructions to find out what the specific code means and whether you can fix it DIY or if a professional will be required (which is usually the case for fixing error codes).
If all is well with your boiler, double-check that your thermostat is on.
If it is and you have a wireless thermostat, it might be worth replacing the batteries, particularly if it’s been some time since the existing ones were added.
You might find that simply swapping out the batteries for new ones will fix the problem.
In general, it’s best to replace the batteries of a wireless thermostat every six months.
Not Giving Your Thermostat the Right Commands
DIY-friendly fixes? Yes
There is a range of scenarios where inputting incorrect instructions can prevent your thermostat from working properly.
For one, if you accidentally set the temperature too low, it may be the case that your thermostat is working but following your accidental orders.
Another not-so-uncommon mistake is for thermostat users to accidentally set their desired heating preferences into the hot water schedule and vice versa.
The older the model, the more likely it is to automatically follow your commands without kicking up a fuss in some form or another when you’ve put in the wrong ones.
However, one way or another, it’s worth checking the settings on your thermostat to see if anything looks off.
If you’re finding it a bit difficult to navigate each menu and decipher all settings, have a look at the manual and it may help you find the problem hiding somewhere in the settings.
The Inside of Your Thermostat Needs a Clean
DIY-friendly fixes? Yes
Another simple step worth trying (if the above efforts fail), is to brush the inside of your thermostat’s control panel to rid it of debris.
Since the accumulation of debris inside a thermostat could result in various issues, a quick clean may be enough to reconnect your boiler and thermostat.
However, extensive debris damage may necessitate a new thermostat.
Your Thermostat is a Bad Location
DIY-friendly fixes? It Depends
It’s essential that your thermostat is situated in the right location.
This is because, if poorly located, various forms of interference can prevent it from reading the temperature of the room, which is necessary for the device to do its job and execute commands.
Among the sources of interference that could prevent a thermostat from accurately measuring the room temperature are:
Direct sunlight landing on your thermostat (even if only at some point during the day)
Nearby electrical equipment
Temperature extremes
Draughts which are often the result of poor insulation
If you suspect that your thermostat is in a poor location, you may be able to relocate it DIY.
However, if you have a wired thermostat, you must hire a professional to relocate it to a suitable spot since this work would involve electricity.
An Issue with The Thermostat’s Wiring
DIY-friendly fixes? No
If you have a wired thermostat, it’s also possible that there is an issue with the wiring.
The three likely issues that can arise here are that the thermostat was wired incorrectly, a part has experienced damage or the unit is simply outdated.
Whatever the case, as you might expect, if there is a problem with the wiring of your thermostat, you must hire a professional to fix it.
Obviously, you may not be able to tell that there is an issue with the wiring but if you’ve exhausted all DIY-friendly options and a wiring problem is indeed the culprit, the contractor you hire should be able to figure this out pretty fast.
Thermostat is On Its Last Legs
DIY-friendly fixes? No
While this is not among the most likely explanations, it may simply be the case that your thermostat is too worn down to do its job properly.
If your thermostat has essentially been thrown in the towel, you’ll need to have it replaced by a qualified professional.
Your Boiler is the Real Culprit
DIY-friendly fixes? No
Another explanation which is thankfully the least likely one is that there’s a problem with your boiler.
Boiler issues that may prevent it from responding to your thermostat could range from a wiring issue to a faulty PCB to your boiler being completely beyond economic repair.
You’d have to consider yourself the winner of the anti-lottery if the latter scenario turns out to be the case!
Obviously, if the issue lies with your boiler, this will need to be addressed by a qualified heating engineer.
Related thermostat guides:
Cost of Hiring a Professional to Fix a Thermostat on Boiler Not Working
Starting with the price of labour alone, it costs approximately £30 to £60 per hour to hire a heating engineer in the UK with electricians charging a similar rate.
While prices are relatively high in the southeast of England, areas such as northern England, Scotland and Northern Ireland feature below-average labour costs.
Of course, the cost of having a professional fix a thermostat-boiler communication issue may also see the addition of supply costs, but this will depend on the specific job.
Here are the costs of a professional fixing a thermostat-boiler communication problem:
Fixing a simple thermostat issue (e.g., cleaning the inside of the device) - £30 to £60
Relocating your thermostat - £30 to £120
Solving a problem with your thermostat’s wiring - £30 to £180
Replacing your thermostat - £150 to £440
Fixing a faulty boiler PCB - £60 to £240
New PCB for boiler - £490 to £800
Fixing a boiler error code is far too dependent on the nature of the issue
Replacing an entire boiler - £800 to £2,800
Related thermostat reading:
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