Central Heating Boilers

The boiler as we mostly it comes in a huge variety of shape, size and colour (seriously – from shiny white through blue red orange and of course my favourite – deep rust – see below).

An old and tired boiler

Boilers can be fired on natural gas, LPG, heating oil (28 sec kerosene), biomass and even electricity.

Essentially a boiler is a simple system whereby water is heated and then circulated through the treated spaces or stored in a tank for later delivery to the heating system or taps.

traditional central heating boiler system

Atmospheric Boilers

The vast majority of boilers that I find on my surveys are atmospheric low pressure hot water systems delivering heat to the property via radiators, UFH or FCUs.

UFH = under-floor heating     /     FCU = Fan Coil Units

An Atmospheric boiler draws in combustion air and discharges flue gases without a fan.

Larger industrial boilers tend to be Forced Draft which uses a fan to raise the pressure of the fuel and combustion air prior to ignition. 

Obviously this is a simplistic over-view and I am not going into the differences between low, medium and high pressure systems at this time. If you wish to discuss this call me.  

So, a boiler is a box wherein water is heated by a flame created by burning air and fuel and the resulting hot water is used to heat living / working spaces or goes to storage.

Boilers can appear complex – they are hot and often noisy – they tend to be looked after by engineers who dabble like Professor Snape in the dark arts.

In reality they are pretty simple bits of kit that should not be scary and should not be viewed as “rocket science”.

Problems with boilers 

The first major problem I almost always encounter is a serious lack of servicing data.

Flue gas analysis dockets for example.  The last flue gas analysis should be taped to the side of the boiler casing so that you can immediately see operational efficiency.

Why is it so rarely to be found? 

Second frequently observed problem – boiler casings or their lack of.  The casing is there for a good reason – it is insulated and prevents radiant losses to the boiler room.

Please please please put the casing back on when you have finished looking at the inside of your boiler!

Then we get onto the thorny issue of inefficiency. 

INEFFICIENCY I hear you shout – not my boiler – I have a brand new all singing all dancing, fully condensing with bells attached, optimised, compensated, heat recovered, balanced flued, triple insulated, ideally located and ventilated, oft-serviced, index-linked top of the range model – blah blah blah – maybe.  

There are of course some very good systems out there, well maintained and set-up to cater for actual demand on site but trust me – these are the minority. 

Whether it is lack of insulation, shoddy or non-existent servicing, poorly maintained controls, badly set time-clocks (even if it just forgetting to spring forward or fall back), over-sizing, under-sizing, failure to address return flow temperatures so that condensing does actually occur, no lagging on pipes, valves, flanges or behind radiators – crikey the list just goes on and on.  

I have access to a variety of solutions to all of these issues – from simple Valve-Wrap and Climaflex pipe-wrap to Load Compensating controls that work hand in hand with your Building Management System.  From behind the radiator insulation panels to Radiator Fans that boost the heat input to the treated spaces.

behind radiator insulation helps the boiler work less hard pipe-wrap helps the boiler work less hardvalve wrap helps the boiler work less hard boiler programmer - makes sure the boiler works only when it needs to

Boiler Controls

There are any number of myths and legends surrounding boiler control – and retrofit boiler controls – here are just a few of them – laid out and busted.

Time-clocks are infallible!  The number of times I go to a property and find that the occupiers rely on time-clock settings that may have been programmed before the first moon landing (ask your Dad if that means nothing).  Time-clocks often default to factory settings if there is a power cut.  Many timers show Mon-Fri and Sat-Sun on first run through but on second run allow you to programme each day independently – why fire up the boiler on a Sunday if you are closed?  If you close your shop at 17:30 try turning off the heating at 16:.30 and the hot water at 15:30 – just a suggestion and each building is different but hey – think about it.

The Building Management System looks after the boiler – a BMS is essentially a very sophisticated time-clock – ok ok if yo sell BMS systems you will of course argue about that and I know that they actually do far more but – aside from allowing you monitor and switch things on and off the BMS often doesn’t look at individual boiler settings and so once the BMS has turned a boiler ON it has very little to do with it until it turns it off again – so it is the bit in between that interests me.

Dry Cycling – this is an oft used term that describes burners firing when there is no true heat load – and it is caused by standing losses from the system (for example, unlagged pipes, poorly insulated boiler casings, poorly set-up internal thermostats). It can be readily overcome to achieve substantial savings by retrofitting load compensating controls – self-learning energy saving systems that monitor individual boiler temperature profiles, reacting appropriately to return flow temperatures to operate burners only as and when needed.   

Snake Oil – never fall for the snake oil salesman

  • magnetic devices that miraculously enhance burner efficiency (they don’t!)
  • additives that increase the thermal efficiency of your fuel (they don’t!)
Snake Oil is bad for you and certainly bad for your boiler

If you have a boiler and you would like to save some money in the operation of your heating system, get in touch!

Electric Boilers

What exactly is an Electric Boiler?  Well as my lovely customer Roger Still will tell you – they are “hellish beast that cost the earth to run and don’t heat the house properly!”

Fortunately for Roger help was at hand and I have managed to find him and his wife an Air Source Heat Pump (air to air ducted through the house) coupled to a Rointe digital hot water cylinder.

Like all things however, horses for courses.  There are times when an electric boiler is your only option and so if you in that position a wall mounted ultra-slim vertical assembly requiring very simple pipework connections and complete with state of the art electronic control system is probably your best bet.  Essentially they work by passing cold mains water over replaceable heating elements housed in an insulated steel heat exchanger.

I am aware of them in sizes from 2kW – 12kW and because they are 99.8% efficient they offer a great alternative when mains gas is not available and it is a hot water system you require.

There are several systems on the UK market and if you care to email me with your enquiry I can send you details of those that are suitable for your property.

electric boiler