3 Reasons your radiators are not getting warm

cold radiator north gas

Lets face it, at this time of the year with the colder weather, keeping your home warm is a top priority. You’ve gone and flicked the heating back on for the winter, cranked up all the thermostatic radiator valves, only to find that one or all radiators are still cold! 

Before the panic sets in that you may need a new boiler, you may want to read the top 3 most frequently asked questions we get from customers on cold radiators and our advice on what to check yourself before you call a plumber.


#1) Why is my radiator cold at the top and hot at the bottom? 


If your radiator is “half cold” (cold at the top and hot at the bottom) this is often due to trapped air in the system. This can be easily fixed by simply bleeding the radiator within a few minutes. 


If you have bled the radiator and eliminated the fact that there could be trapped air but you are still having the same issue, you should then consider the following;

If you have an older radiator, it may be that there is a build up of rust and you may, therefore, want to consider removing the radiator and flushing it outside using clean water (if you’re used to DIY). This obviously hasn’t got the same pressure or effectiveness that power flushing has and will only target one radiator but it may do a good enough job to remove the radiator sludge for your one problem radiator.


#2) Why do I have one cold radiator?

Often when there is one cold radiator in your home that doesn’t heat up properly, this can be due to the radiator valve on the affected radiator not being completely open. 

If you have opened the radiator valves and are still finding it isn’t heating up, this may be due to the fact that the heating system throughout your home isn’t balanced properly.


Simply put, if your boiler is located on the ground floor, the water from the boiler naturally gravitates upwards throughout your home which often can result in more heat to upstairs radiators than the ground floor radiators. To fix a cold radiator in your home, try by firstly turning all the radiator valves throughout your house completely off, starting upstairs and working your way downstairs, with the exception of the affected radiator. Once all valves are turned off, run your heating until the affected radiator heats up. Then begin to gradually turn each of the other radiators back on untill all radiators are getting upto the desired temperature.


#3)Why are all my radiators not getting hot?

If you find that all of your radiators are not heating up properly or at all, this doesn’t necessarily mean that you will need a boiler replacement. Over time central heating systems will produce sludge and debris which can sit at the bottom of radiators, resulting in heating systems not working as efficiently and to full capacity. Sludge and debris in your radiators not only cause a nuisance by not heating your home properly but will also put a strain on your boiler, costing you more money in energy. You may have heard of the term Powerflush when researching into how to fix central heating or radiator problems in your home. Put simply a Powerflush is a simple procedure using a high pressure machine and chemicals that is carried out by a trained plumber to cleanse your central heating system of sludge, rust and debris.


Common signs that your heating system is in need of a powerflush may include cold radiators, brown discoloured water flowing out when bleeding radiators or excessive noise coming from your boiler. 

With North Gas, a complete powerflush to your system can be carried out usually within half a day by one of our skilled and friendly team, removing all sludge and blockages from your system and avoiding breakdowns further down the line.


If you’re ready to give your central heating system a clean bill of health, contact us for a free estimate. 

Do you need any further advice on central heating issues before you book your powerflush or repair? 


North Gas are on hand to provide FREE no obligation advice over the phone, email or even in person by calling out to your property.

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