Cylinder Boiler (300L) vs Space Saving Boiler (80L)

In most countries you have a choice of Combi Boilers, Heat Only Boilers and System Boilers. In France, your choice of Electric Boilers is somewhat limited. They do not have heat only or combi boilers, that supply hot water on demand as you need it. We needed to chose between a huge 300 litre Cylinder Boiler and a 80 litre Space Saving Boiler. What are the Pro’s and Cons? The purchase prices were identical, what were the running costs like? Does either have a drawback?

Types of Boilers Not Available In France

As mentioned they do not have conventional direct electric, heat only and combi boilers commonly available in France, as they have in the UK.

The French power system is usually limited to a maximum of 12KVa per house so connecting an electric shower or a 18KW instantaneous water heater is not an option. Instantaneous water heaters are highly efficient, but they take large power spikes over a short period of time from the power network. The French electricity network would not be able to cope with this short term demand. With these types of heaters virtually no heat energy is lost over time making them highly energy efficient over the year.

Instantaneous water heaters would not be an option in France. They exceed available power network capabilities

What size Boiler Did I Need?

Ours is a four bedroom house of nearly 200m2. We would need between a 200L and a 300L cylinder boiler or live with a 80L space saving boiler and rely on our log burning fires. The long term plan is to get another log burning boiler for the caves.

Number of PeopleCylinderSpace Saving / Flat
150L
1 to 3100L40L
2 to 3150L65L
3 to 4200L80L
5 to 6300L

Heating Elements – Pros and Cons

Heater Element
– Directly in contact with the water
Heater Element
– Protected from limescale by an enamel coating
Soapstone Resistance
Protected in a Sheath
– limits the formation of limescale
– can be replaced without emptying
– quieter
Soapstone Resistance
Protected in a Sheath
– limits the formation of limescale
– can be replaced without emptying
– quieter

What Kind of Anode?

Space saving and Cylinder boilers both use different kinds of anodes. These effect the lifetime and maintenance cycles of your boiler.

Magnesium Anode

Consumed by absorbing corrosive currents. Requires oil change every two years.

Electronic Titanium Anode

Analyzes and cancels corrosive currents:

  • More effective protection
  • indestructible and maintenance free
  • gives healthier water

Boiler Comparison

Our house has very thick walls and floors. Even during the winter when the temperature dropped to -10°C the inside of the house did not drop below 6°C and it had been abandoned for 30 years. Therefore, the house obviously has some form of thermal retention. Water heating and getting the roof insulated is the main issue.

CylinderCylinderCylinderSpace SaverSpace SaverSpace Saver
AcapulcoAcapulcoAristonAristonAristonSauter Atami
ResistanceSoapstoneSoapstoneSoapstoneEnamelSoapstoneSoapstone
AnodeMagnesiumTitaniumTitaniumMagnesiumTitaniumMagnesium
Fuse Rating16A16A16A
Energy ClassC
2730Kw per Annum
C
2713Kw per Annum
C
2713Kw per Annum
B
2713Kw per Annum
B
1291Kw per Annum
C
2713Kw per Annum
Lifetime••••••••••••••••
Ease of Maintenance•••••••••••••
Accessories included•••••••••••••••••
Tank Guarantee5 years5 years5 years7 years5 years5 years
Parts Warranty2 years2 years2 years2 years2 years2 years
Support Guarantee1 year2 years2 years2 years2 years2 years
Type of ProductCylinder Boiler
100L
150L
200L
300L
Cylinder Boiler
100L
150L
200L
300L
Cylinder Boiler
200L
300L
Space Saver
65L
80L
Space Saver
65L
80L
Space Saver
65L
80L

Energy Ratings

Essentially, energy in equals energy out. Electric boilers are 98% efficient whereas other types of boilers such as fossil fuels are far less efficient. Much more energy can be lost in noise, light and thermal transfer process. Unfortunately, energy costs make electric a very valuable resource. Energy ratings and annual power consumption figures are a vital consideration factor when choosing a boiler.

Cylinder Heaters vs Space Savers

Cylinder heaters obviously have a massive amount of water that can run radiators, baths, showers etc. They do however, need to be kept on virtually 24/7. Given today’s energy prices, that can be expensive. Modern cylinder heaters are much better insulated than past heaters but it still pays to insulate them in approved thermal jackets. They will radiate heat unnecessarily into the atmosphere. They are essentially another giant radiator and many French people treat them as such.

A space saving heater can be mounted vertically or horizontally on the wall inside a cupboard in a kitchen or in a bathroom. It can be mounted very close the the target, such a above sink, next to a bath. This also keeps pipes really short. Pipes being another source of unwanted radiant heat loss. Space saving boilers can be bought cheaply and the installation costs can be low. Providing you are economic with your hot water usage, they can be a cheaper alternative to cylinder boilers in certain situations. Space saving heaters can heat up much quicker from cold. They often have standby and economy modes, whereby a user can effectively turn them off, press a button and have them back to full temperature within the hour. An 80L space saving heater would have enough water to fill an entire bath with piping hot water.

Cheaper Overnight Electricity Tariffs

One advantage of the larger cylinder boilers is that you can use overnight tariffs to heat your water. If using overnight tariffs it is absolutely imperative that you water tank is up to date and is properly insulated with an approved water jacket. All water pipes must be insulated.

Some of the simpler space saving boilers have only a thermostat simple dial to control temperature with no time clock to regulate when they come on. They would not have the reserves to run a radiator system for a large house during the day.

A space saving heater is primarily designed to heat water for baths and showers, it is not for large radiator networks; it will be running constantly. For such radiator networks, having a reserve of heat from a larger cylinder style boiler; heated on cheaper overnight tariffs; would have advantages.

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