What Speed to Set a Central Heating Pump (Expert Guide)
So you’ve bought a central heating pump. You’ve installed it. And now you need to get it working.
But if this is your first time setting up a central heating pump, you will no doubt be confused by the variety of speed settings available.
“Why do central pumps have variable speed settings?”, “Is there a special speed setting for my home?” and “Should I just bang it in the middle and be done with it?”
That’s why we’ve developed this guide to central heating pump speed settings. Taking you step by step through the boiler pump set-up process, this guide will help you optimise your central heating pump for maximum efficiency.
Why does a central heating pump have more than one speed?
Every central heating system is different. One home has 20 radiators, while another has 24. One home has 30 metres of piping, while another has 130 metres of piping. That’s before you even consider the layout of the home and the type of boiler you have installed.
Each of these elements impacts how quickly and easily water can circulate your home. In one system it may take one minute, while in another it may take 5 minutes for the water to circulate fully.
For this reason, there will never be a perfect pump for each home.
So, to save themselves from the GIGANTIC task of developing millions of pumps for different homes, the clever little central heating pump manufacturers developed a variable speed dial that allows you to easily increase and decrease the speed of water circulating your home depending on your needs.
What happens if the central heating pump is running at the wrong speed?
Firstly, setting your central heating pump to the wrong speed is not the end of the world. It’s not a major issue, and it can be easily fixed. However, this may be why many plumbers don’t take speed settings very seriously.
The usual attitude is “set the pump to medium and hope for the best, lads”.
Unfortunately, this attitude can cause homeowners a variety of problems.
For example, if the speed setting is too fast:
- You will be wasting a lot of electricity and driving up bills (central heating pumps can account for 10 to 15% of your electricity consumption)
- The pump will generate a lot of unnecessary noise
- The water will return to the boiler too warm. In severe cases this can damage boiler components - The pump is more likely to break due to the increasing demand in performance
Surely we should set the pump to the lowest speed setting then?
Well, no, this can cause another set of problems. These include:
- The pump is made redundant as the water cools before reaching the radiators
- In some cases, the boiler can overheat and cut out
SO WHAT DO WE DO?!?
How to find the best speed setting for your central heating pump
There are two ways to set up a central heating pump. The first is quite simple and merely requires setting the pump to the slowest speed and then increasing the speed slowly over time. However, this method takes a little too long for our liking and is, frankly, far from accurate.
Plus, the second method is far quicker albeit a little more complicated.
1) Open all radiator valves
For this method, ensure all the radiator valves are fully open. Done? OK, Step 2.
2) Set the thermostat to maximum
You want to test the pump at maximum temperature, obviously.
3) Set the speed to maximum
Now set the pump to the maximum speed setting. This may seem counterintuitive, but it will give you have an accurate idea of how hot the radiators should be at the maximum temperature.
4) Wait 10 minutes
Wait for the radiators to heat up. At maximum speed, this should take less than 10 minutes.
5) Turn the speed to minimum
OK, now turn the pump speed to minimum. At this point, we’re starting to test the circulatory requirements of your system.
6) Wait for 20 minutes
Now, wait for 20 minutes. What should you do in those 20 minutes? Make a brew. Watch Corrie. Anything but play with the central heating pump.
7) Are the radiators still hot?
OK, 20 minutes is up. Put the brew down. Are the radiators still hot?
8) If yes, leave the setting. If no, set the pump to medium setting.
If the radiators are still hot, then bingo, you can leave the pump at the current setting. However, if you think the radiators have cooled, then turn the pump speed to medium.
9) Wait for 15 - 20 minutes
Now, wait a further 20 minutes. Again, make a brew. Watch Corrie. Anything-but play with the central heating pump.
10) If the radiators are still cool, set the pump to the fastest speed setting
Did the radiators heat back up? Or did they remain cool? If the temperature has barely changed, set the pump to the fastest speed setting.
If you’re struggling for advice, ring our dedicated pump experts for free advice on 0800 112 3134 or 0333 577 3134.
We’re open Monday to Friday 07:00 - 17:30 and Saturday 08:30 - 12:30.