No Hot Water From Your Boiler? Check This Before Calling An Engineer

In this 5-minute guide to boilers with no hot water, we’ll talk about the possible reasons you’re getting no hot water from your boiler, and recommend solutions.  

Get the Best Gas Safe Engineer to Fix a Problem With No Hot Water

Before we carry on, any repairs or replacements will require a skilled Gas Safe engineer to look at the problem; you can book one in here.

With trusted heating engineers on hand, you might consider upgrading your old, outdated boiler with a high quality Worcester Bosch from Heatable. They’re available at highly competitive prices, with flexible financing and 10-year warranties. Found a better price elsewhere? Heatable will match it!

And if you’re looking for faults not listed below, checkout our guide to boiler problems.

No Hot Water and No Heating

Of all the diagnoses, this is the hardest one to pin-point without inspecting the boiler and central heating system. The possibilities are pretty much endless, but only a few require professional services from a Gas Safe heating engineer.

#1 – No Power to Boiler

Is your boiler control panel blank? Are the power lights off? If you’ve answered yes to either of these questions, there may be a problem with the energy supply.

Take a look at the control panel on your boiler. If you are getting adequate power, the panel should be functioning properly and displaying control options.

The Fix: Check our guide for boiler power issues.

Electricity supply issues are actually quite common, and are easy to assess and fix. We’ve created a guide specifically for users with no power to their boiler here.

#2 – Faulty Heating Pump

On each boiler, there is a “flow” (hot water supply) and a “return” (water returning to the boiler, after circulating around the central heating) pipe.

Your flow pipe should be hot. The return pipe should be a little bit cooler; radiators and pipework will take some of the heat out of the water as it travels round the system.

If neither the flow or return are hot/warm, there’s a chance the pump isn’t circulating.

The Fix: Check our guide for heating pump problems.

Need to diagnose a faulty pump? We’ve created a guide to central heating pump problems here. Within the guide you can find more details about the causes of pump problems and some suggestions for how to fix them.

#3 – The Pilot Light Has Gone Out

The pilot light is the small flame you see in your gas boiler. If this has gone out, it’s likely a fault code has appeared (check your owner’s manual to see what the fault code means).

The Fix: Contact a gas safe engineer.

We can’t advise fixes on gas-related issues. Do not attempt to fix or correct pilot light problems on your own — always contact a Gas Safe registered engineer.

#4 – Hot Water But Faulty PCB/Display Panel

If you have power, and can hear internal parts working/moving, there’s a good chance you’ve got a faulty PCB and display panel.

Like other components in the boiler, they do break over time. This process can be sped up if your boiler is leaking water that’s made its way into the control panel.

The Fix: Check and replace your boiler’s panel.

Due to the complexity of the boiler’s display panel, the best option is to replace it. To gauge the boiler pressure, you have to be able to check the relevant data provided by the pressure gauge to the boiler’s panel.

The PCB is incredibly expensive — you can expect a bill of around £500. If your boiler is over 5 years old or out of warranty, depending on the condition of other parts, it might be worth considering a replacement. A new boiler might cost less in the long run.

Typical installation prices start from around £2,000+. However, we’d recommend checking out Heatable, an online boiler installation company. They’re one of the cheapest for Worcester boiler installations and you can get a fixed price quote online in less than 2 minutes here.

#5 – Faulty Programmer or Timer

No hot water and no heating could mean that you have a faulty timer or programmer.

The Fix: Reset the system.

Check the boiler manual for details on how to reset the programmer and timer. Typically, there will be some sort of a reset button.

And if you’ve had a power cut, this temporary loss of electrical power supply can mess with the time/date stamp on both devices. If you’ve programmed your heating and hot water, it could be set to the wrong time. Check time/date stamps, and adjust the boiler settings if necessary.

#6 – Frozen Condensate Pipe

If you’re getting no hot water and no heating on cold mornings, or during winter, there’s a good chance the condensate pipe is frozen.

The condensate pipe vents flue gases from your property, and these are prone to freezing.

The Fix: Clear Blockage

Check the pipe for blockages/frozen debris. Clear the blockage and slowly thaw out the pipe — doing so should resolve the lack of hot water.

#7 – Boiler Lockouts

A boiler lockout is a shut-down procedure. It’s a shut-down sequence initiated by the boiler when it realises there’s something not quite right.

The Fix: Check Error Code

There’s a tonne of reasons a boiler can lockout; some have been mentioned above.

The display panel will show a fault code. With that information in hand, head over to our page on common boiler lockout causes and fixes here.

#8 – Low Or No Pressure In The Boiler

Your boiler produces pressure when it’s heating water. If you have no hot water or central heating, it could be due to a loss of pressure.

The Fix: Get Help From An Expert

We’ve created a guide to why boilers lose pressure, and the fixes here.

No Hot Water But Heating Works

When there’s no hot water but the heating works, this is usually a sign of a faulty diverter valve.

However, it’s important not to jump to conclusions. We’ve had people contact us in the past with the same “heating but no hot water” problem. Their engineer fitted an expensive diverter valve, and it didn’t fix the problem.

The Fix: Contact an Expert

Here’s a guide to diagnosing a faulty diverter valve.

Remember, don’t jump to conclusions. There are other reasons you could be getting no hot water from a combi boiler, but the heating is working. For example, faulty S-plan, Y-plan, or zone valves could be the root cause.

My advice would be to contact an boiler engineers for a quote before spending any cash on repairs. If you’d prefer a replacement, you can get a price online here.

No Hot Water But Cold Water Works

When you get no hot water, but the cold water works, there are a few potential problems.

First, as this is quite a broad issue (it’s easier to diagnose when seeing the heating system), check out the two sections above:

• No Hot Water and No Heating
• No Hot Water But Heating Works

Those cover actual boiler problems. But, we’ve been to properties where it’s not the boiler’s fault at all.

Have you smelt gas and turned off the gas valve?

If this is the case, you’ll get cold water from the hot tap, but as there’s no fuel for the boiler to burn (and heat the water), you won’t get hot water.

Did you try to increase the water pressure of the boiler via the filling loop and close off more than one valve?

In this scenario, the gas lever is probably still open and ready to fuel the boiler, but the water supply for the hot has been turned off.

The Fix: Check Water & Gas Levers

For the boiler to heat water and send it to your hot tap, it needs two things:

• Water Supply
• Gas Supply

You’ll want to be sure that both of these levers are open.

If your property has no water coming from the taps at all (perhaps you just moved in), there’s a good chance the mains stopcock (sometimes there’s more than one) has been turned off.

Make sure to turn this back on to get a supply of water to the boiler, taps and shower.

No Hot Water In Shower Only

If you’re getting no hot water in the shower only, but it works elsewhere, there are a few explanations:

• The mixing valve in the shower is stuck or broken
• Anti-scalding device is set in the wrong position

The Fix: Replace Mixing Valve

If the mixing valve is stuck or broken, it needs to be replaced or fixed. Personally, for the sake of what they cost, I’d get it replaced.

On most newer showers, you’ll have an anti-scalding device built in. If this is set too high, you won’t get your hot water from the shower. It’s located behind the knob used to turn the heat of the shower up and down; adjusting this setting can sometimes fix the problem.

That said, it’s unlikely this has suddenly just changed; so, unless you’ve just moved in, we’d head for the mixing valve.

If you would still like an engineer to come and check out your boiler,  you can book one to take a look here.

Prefer a replacement boiler? We’d recommend getting a quote price from Heatable’s boiler calculator.

What’s Next?

Whether you’ve got no hot water and heating, or just no hot water in your shower, we hope our guide has helped.

If you’re still stuck, drop a comment below and we’ll get back to you as soon as possible.