Heating Solutions

How to Replace a Central Heating Pump

How to Replace a Central Heating Pump

The central heating pump is the beating heart of your central heating system, efficiently circulating warm water around your system to heat your radiators and keep your home comfortably warm.

But what happens if you have a problem and the central heating pump fails? If you’re a competent DIYer, this is a job you can tackle yourself if you follow a few relatively simple steps. Otherwise, it’s time to call the plumber.

Why Did My Central Heating Pump Fail?

Central heating pumps fail for a variety of reasons. The most common are corrosion and a failure to flush through the system on a regular basis. If your pump isn’t circulating water round the system and the body of the pump feels hot, then you’ll need to fit a replacement.

If your existing pump has lasted for 30 years, then you may wish to replace it for a more energy-efficient model.

Choosing Your New Pump

If you’re replacing an older pump, check if it’s a standard size. If not, you may need special adapters.

Measure your old pump, and make a note of the maker’s name and any settings. It may be easier to take a photo.

Choose energy-efficient central heating pumps and don’t oversize – a professional will advise you on the best replacement pump.

What You’ll Need

You’ll need to equip yourself with the following tools and equipment:

– A new pump – choose the most energy-efficient model you can afford

– A plumber’s tool

– A screwdriver – use an electrical one

– A bowl or an old paint tray and some towels

– Paper and pen/your phone

First Steps

First, close down the central heating system by switching off the electricity. Never undertake a pump replacement while the current is running.

Now make a diagram of the wiring schematic so you’ll know how to connect the new pump. You could even wrap different colours of electrical tape around each wire for ease of reference and so you’re absolutely clear on what goes where. The simplest way may be to take a photo on your phone for reference.

Removing the Old Pump Unit

Now you’re ready to remove the faulty pump. First, close the service valves, which you’ll find on the body of the pump, either by hand or with your plumber’s tool. If no valves are present, you’ll need to drain your heating system completely.

To avoid any potential spillages, place an old paint tray or a bucket under the pump. Now locate the union nuts which hold the pump in place.

Gently turn the nuts anticlockwise (remember: left to loosen, right to tighten), and then remove the failed pump.

Replace the Pump

Ease the new pump into position, ensuring it fits snugly. Don’t be tempted to re-use washers, as they can can contract over time – fit new ones in the union nuts for a watertight seal. Tighten the nuts finger-tight before finishing the job with your adjustable spanner. Now you can check for leaks by turning on the service valves or refilling the system.

Next, you’ll need to make sure the unit is bone-dry before reconnecting the wiring according to the wiring diagram you made earlier.

Testing Your New Pump

Now to get your new pump up and running. Switch the electricity back on and kick-start the heating system by turning up the thermostat.

Now you’ve got the central heating system up and running, check for any leaks or significant discharge of water. You may want to call a plumber to make sure there are no problems with the new installation.

Complete Your Installation

Finally, it’s a good idea to bleed the system to make sure there’s no trapped air. Your pump will have a bleed screw that you turn anticlockwise until you hear a hiss. You’ll probably need to bleed the radiators as well to ensure the whole system is balanced.

Bleeding the system will help to safeguard against corrosion and protect your newly installed pump.

Maintaining Your Central Heating System

It’s a good idea to flush your system through occasionally and to add a descaler and a rust inhibitor to it. Some descalers need neutralizing before an inhibitor is added, and you should always add the same inhibitor as is already in the system. Check the manufacturer’s instructions.

Make sure your central heating system is serviced by a qualified professional on a yearly basis to keep it running efficiently.

Ask the Professionals

If you do run into problems with your central heating pump, Anchor Pumps have a comprehensive range of replacement pumps, including highly rated energy-efficient Grundfos pumps. Contact us for more details 0800 112 3134.

How to Circulate Heat in a Large Building

How to Circulate Heat in a Large Building

There are a number of solutions to circulating air in a large building, whether that involves commercial premises or simply a large domestic dwelling with high ceilings.

Common Central Heating Systems

Most central heating systems are based on a boiler that heats hot water which in turn heats your radiators. Heat exchange pumps borrow heat from the outdoor air and discharge it indoors. Secondary heating may take the form of wood-fire boiler, gas fires and electric space heaters.

In a conventional boiler system, the hot water is circulated by means of a heat circulating pump. A Grundfos pump is particularly efficient and can save up to 80% on your energy bills. A heat exchanger is basically a two-way air conditioner, though ground source heat pumps borrow heat from the ground.

How a Circulating Pump Works

The circulating pump pushes hot water out through the heating system and pulls cool water back so it can be reheated. The pump works on electricity, as part of a closed or open heating system in conjunction with the boiler, thermostats and valves to heat your building.

When the thermostat calls for heat, the valve is opened and the pump is activated. The performance of the pump is rated on its flow performance, which is a function of flow rate (the amount of water that can be pushed through the system per minute) and head pressure.

The larger the building, the greater the flow performance and the higher the pressure required.

Wet Heating Vs Warm Air Heating in Commercial Spaces

The most cost-effective way of heating a large commercial space is usually a heat exchanger. This will then circulate the warm air throughout the building via a series of vents.

Because warm air heating produces a dry heat, it can be valuable for premises that are used for storage, like warehouses. It’s also better suited to offices that run a lot of computer equipment.

However, in large spaces with little insulation, wet heating may be the preferred solution. Functioning like a domestic boiler based system, wet heating can be more economical for an office.

Underfloor Heating or Radiators?

Underfloor heating is generally a preferred system in new-builds, as pipes to carry hot water can be fitted during construction.

Underfloor heating gives an even heat distribution, maximises wall space and minimises hot surfaces. Heat is radiated directly from the floor and then rises to the top of the room.

Radiators, on the other hand, use convection to transfer heat energy, which results in the warm air being stored at ceiling height while cold air remains at floor level.

Wet underfloor heating systems are still dependent on a boiler and circulating pump like other wet systems, but they transfer energy more efficiently. They are particularly suitable for open-plan spaces with high ceilings because of the way radiant heat transfer works.

As with all heating systems, the more efficient your insulation, the less heat loss you will experience, and the more effective your heating.

Creating Zoned Heating

In larger homes or commercial premises, different heating zones will need to be created using either multiple valves or multiple circulating pumps to control each zone.

Multiple heating zones require separate thermostats and timers to function correctly and may be set up in a series of configurations, with S, W and Y being the most common.

The creation of multiple heating zones is the most energy-efficient way to heat larger domestic and commercial spaces.

Choosing the Right Pump for the Job

It’s important that you don’t oversize your pump if you want to maximise energy-efficiency. However, choosing the right circulator pump to circulate heat in a large building is a job best left to the professionals.

That’s where we come in. At Anchor Pumps we carry a range of circulating pumps suitable for larger domestic and commercial installations. Contact us and we’ll be able to advise you on the best way to maximise energy-efficiency whilst keeping the circulation of heat at a comfortable level, whatever the size of the building.

Is it More Energy-Efficient to Keep the Heating on?

Is it More Energy-Efficient to Keep the Heating Running-

It’s a long running debate: is it better to leave the heating on all day or only switch it on when required?

The ‘Leave It On’ Argument

According to the Energy Trust, 38% of us believe that leaving the heating on low all day is more energy-efficient than turning it on and off constantly. The same number of people leave their storage heaters switched on at all times.

They argue that the boiler has to work harder every time you switch it on. However, if you leave the heating on while you’re not in the house you’ll be using energy all day long, and that’s what you should be focusing on. You’ll need to balance personal comfort with energy-efficiency and think about using an energy-efficient central heating pump to save water and energy.

Energy and Heat Loss

However well insulated your home is, you’re always losing heat and energy – around 33% through the walls and 26% through the roof. Whenever you open your front door or drain the sink or bath, you’re losing heat from your home, which you’ll need to replace by turning up the thermostat.

Basically, heat loss is proportional to the difference between the temperature inside your home and outside. The greater the differential, the more heat you lose. The longer you maintain the differential, the more heat you’ll lose and the more energy you’ll use to replace it.

Even in a well-insulated home, your heating system will use energy just to maintain a constant temperature – and that’s expensive.

If you work during the day, it’s far more energy-efficient to put the heating on when you need it. So invest in a smart device so you can make sure your home is warm and comfortable when you step through the door.

Testing the Theory

If you’re still not convinced, you can test the theory for yourself with these five simple steps:

– First take a meter reading.

– Leave your home heating at a comfortable temperature for one week.

– Take another meter reading.

– Set your timer to only come on and off when you need it – again using a comfortable temperature so as not to skew the results.

– Take a meter reading.

Whatever the result – and you’re almost certain to find the second week is cheaper than the first – you’ll know which is the cheapest way for you to heat your home.

Some Heating Facts

Bleeding your radiators, which is simple and straightforward to do, will make a difference to your heating system. So will using curtains – draw them when the sun goes down and you’ll reduce heat loss by up to 17%. Putting furniture in front of your radiators is a no-no, as you’re simply heating the back of your sofa.

Upgrading a boiler that’s 15 years old can save you up to 40p for every pound you spend on heating your home. An A-rated circulating pump can save almost 80% in energy-efficiency over older models and keep your home not only energy-efficient but cosy too.

Insulation is the key to minimising heat loss, so look at insulating every area of your home from your loft to your cavity walls – there are schemes that can help you to upgrade your existing insulation for free. Hunt down any draughts and fit draught-excluding tape to minimise heat loss even further.

Energy Efficiency in the Home

Of course, your heating isn’t the only way you might be increasing your energy bills. Use low-energy light bulbs and fit double or even triple glazing to cut your energy usage.

Turn off you equipment when not in use – standby is a notorious energy hog. Invest in a standby device that will switch off non-essential items but leave your Sky box running so you don’t miss that all-important episode!

The Energy Trust website has some excellent advice and online tools to help you minimise your energy costs and cut your energy bills. Just remember to set your timer or invest in a smart thermostat and stop wasting energy by heating an empty house.

How to Get Your Central Heating Ready for Winter!


Taking care of your central heating system before winter begins is essential. From ensuring that it is not emitting potentially deadly carbon monoxide to obtaining the maximum value from what you spend on energy, getting your system ready for the frosty months should be on the annual “to-do” list. When this is done, homeowners should be able to relax, knowing their heating system is primed to work at maximum capacity over the winter to come.

The Pump Is the Heart

Checking central heating pumps are working correctly is vital, as the system’s pump is like the mechanical heart of your central heating. The pump should not be connected to the electricity supply when it is being inspected or adjusted. Make sure it is disconnected before work begins. Without a capable pump, hot water will not circulate properly. As the pump uses around 15 per cent of the system’s energy, regular maintenance will ensure it is operating well. If not, a new pump can increase the efficiency and performance of your central heating.

Central Heating Winter Must-Dos

Central heating winter preparation includes checking your boiler thoroughly. Your boiler may appear to be in good working order, but it is always a sensible idea to get it inspected by an appropriate qualified engineer at least once a year. The engineer will examine the boiler and clean it where necessary. Doing this on a regular basis could save you cash by avoiding major problems.

Getting this done before winter really sets in is a worthwhile precaution, not only ensuring the boiler is ready for the cold season but also that it is in the best possible condition for the time of year when it will be working its hardest.

Heed Warning Signs

Odd noises, sooty marks or leaking are indications that something may be wrong with the system. Regular checking of your boiler will ensure you are aware of these signs that indicate the system requires maintenance. The more rapidly a problem is found and attended to, the better it is for the system and for you.

Get to Know Your Boiler

It could be useful to read the blog post titled “Boilers and Central Heating Explained”. In this entry the basic types of central heating systems are explained. It is easier to make decisions about maintenance requirements when you know what you are dealing with. For example, it is good to know if your system is open or closed.

Dangers of Not Paying Attention

A boiler that is not operating properly can be producing carbon monoxide gas, which can kill. Part of preparing for winter could include installing a device that triggers an alarm if carbon monoxide is detected. If you have one of these, make sure it is serviced before winter begins. Ideally, it should be examined around once each month to make sure it is working correctly.

Upgrading to a New Model

Eventually a boiler will simply wear out. Then it will need to be replaced, and it is much better to do this before the cold season begins. The new boiler you choose could have a significant impact on your bills and energy consumption.

It is worth looking at the latest models to see which ones are the greenest and most efficient. Other things to consider include a back-up plan. A new boiler can be installed with an electric immersion heater to fall back on should there be a problem with the main boiler, and the family will appreciate this in the middle of winter when otherwise there would be no hot water. This can also be a good option for a larger home with a number of bathrooms when there is heavy demand for hot water.

Breathing Space

To work efficiently, a boiler also requires plenty of ventilation. If the boiler is located in some kind of cupboard that is also crammed with clothing and sports gear, the boiler could benefit from a bit more space. Clear out some of this stuff before winter begins to give the boiler every chance of adequately serving the heating system by allowing the air around the boiler room to circulate. A cramped environment can reduce the lifespan of a boiler and decrease the efficiency of a heating system.

For a warm and trouble-free winter, make sure your central heating is in the best possible condition. To ensure this, call in professionals to check the system and carry out any necessary maintenance.

Common central heating pump problems

central heating pump problemsThe central heating pump is the beating heart of your central heating system. You can find out more about boilers and central heating systems here. But how do you prevent problems from occurring, and how do you deal with them if they do?

Always disconnect the pump from the electricity supply before inspection, carrying out repairs or attempting a replacement.

Pump Not Starting

Is the spindle turning? If not, use the manual handle or a screwdriver inserted in the shaft to start it. Other fixes include increasing the pressure and flushing with water. Do not submerge the pump.

If the central heating system is not calling for the pump to start or a fuse has gone, call a qualified professional to check the wiring.

Humming in the System

The most common cause is vibration from an incorrectly seated pump. Turning the pump down may fix the problem. If not, tighten the bolts. Remember that a correctly running pump will vibrate slightly.

Radiators Heating Unevenly

If the radiators are hot downstairs but not upstairs, your pump could be jammed. This problem commonly occurs when the heating has been turned off for a while – over the summer, for example. You’ll need to locate your pump, which is usually near the boiler.

A gentle tap with a hammer should kick-start it. Otherwise, proceed as for a non-starting pump.

Jammed Propeller

If you’re having work done on your central heating system, then foreign bodies can enter the water supply and jam the propeller. You’ll need to open the pump and thoroughly clean it.

Over the years your system can accumulate grime that can affect the running of the pump. You’ll need to give the entire system a power flush to clean it. Allowing the water to deteriorate and become sludgy can severely compromise the life of your pump.

System Airlock

If air gets trapped in your central heating system during a refill, it can result in no heating. First bleed the radiators with a radiator key, and then locate the bleed screw on your pump.

Slacken the screw, but don’t undo it completely. You’ll hear any trapped air escape, accompanied by a trickle of water. Close the screw and top up the system.

Does My Pump Need Replacing?

There are several instances when your pump cannot be fixed and will need replacing. Internal corrosion will stop your pump’s components working. Corrosion occurs more quickly when a central heating system has not been in use for some time. Make this a priority check when buying an older property.

If the pump is leaking, then it may need to be replaced. This is almost certainly as a result of corrosion which can’t be fixed. If brown liquid is leaking from the start capacitor, or it looks burnt out, you can replace this part only.

If the pump is no longer circulating, the gate valve could be faulty. If this is the case, you will need to replace the pump. If the pump is on but not circulating water around the system and feels hot, the motor may have failed.

How Can I Remove My Old Pump?

If your pump has failed, you will need to remove the faulty pump and replace with a new one. Choose a reputable brand like Grundfos, and make sure it matches the size of the pump you’re replacing. This avoids the need for any adjustments to pipework.

First disconnect from the electricity supply. Then turn off the water supply to the pump by closing any isolation valves. If these are not fitted, make sure you do so for future ease of pump maintenance. Then drain down the pump.

Finally, remove the union nuts, clean the valves and replace the washers.

Fitting a New Pump

Ensure that the direction of the flow markings on your new pump matches the previous fitting before attaching the valves and checking for leaks. Now, with the pump switched off, release any trapped air. Then rewire and switch on the pump.

Throughout this procedure, ensure that everything is dry and there are no leaks.

Service Regularly

Your heating pump will give you several years of service if you keep it and your central heating system well maintained. As it’s the heart of your system, consider replacing an older pump with a newer, more energy-efficient model.

Following this simple checklist will enable you to easily solve most common central heating pump problems and keep your system running at maximum efficiency for years to come.