Maximum current watcher system for our electric boilers

Maximum current watcher system for our electric boilers

So a UK home typically has a 100 Amp supply fuse , this means that all the home electrical appliances , whilst being used simultaneously should not draw over 100 Amps , otherwise the fuse can blow.

Following is a chart showing the electrical ratings of commonly used household appliances –

Firstly Electric Showers- these can have some high loads

Standard Shower Rating Watts (kW)          Maximum load from the supply (Amps)

6kW                                                                      26

9kW                                                                     39.13

9.5kW                                                                  41.3

10.5kW                                                                45.65

11.0kW                                                                47.82

Standard electrically powered items, such as laptops, mobile phone chargers, Televisions (42″ HD), printers and radio’s etc only use approximately 0.5 amps, and don’t generally cause a problem in relation to your electrical loadings, but the following list of appliances and the amps they can draw on a single phase electrical supply, will have –

The largest consumers of Amps are induction electric cookers / standard electric cookers, which typically range from 30 to 40 Amps per appliance depending on their output. Please check your specific model for the amps drawn with the manufacturers data.

Other electrical appliances 

Domestic Electric AppliancesAmps Used
Radiator ( Electric )8.5
Hair dryer10
Washing machine10
Tumble dryer11
Vacuum cleaner9
Radiator (oil filled)13

UPDATE – We have now solved this common problem 
So why does this matter ? Well it matters because the larger the electric boiler you go in size , the more Amp’s you need available to power the boiler . You will generally find that in a standard 100 Amp – 240 Volt , single phased supply property , the largest boiler you can use is a 10 kW Boiler ( now a 15kW boiler-see the update below in red ) – why ? because this boiler will draw 45.5 Amps , which is getting close to half of the supply for a standard UK property , even when you consider a diversity factor ( which in layman terms means that not every electrical appliance would be on at the same time ) you are starting to possibly exceed your supply and tripping out fuses etc.

We now do a new range of electric boilers for central heating and / or domestic hot water, designated the “FHEL” range that can now utilise what we are calling the ” maximum current watcher” – it is basically a releasing relay (restriction of current). The relay monitors and controls the electric voltage in the whole house or flat and in the case of exceeding the permitted values of the electric current it reduces the input power of the electric boiler. All of this is done automatically, without any human intervention needed.This system will not only operate on our 240 volt / 1 Phase Electric boilers , but also our 400 Volt / 3 phase units as well. This now means that you can use our 15kW electric boiler model, in a property or flat with standard 240 volt, single phase with no worries or problems that the unit will trip out the main electric board.

For full details on this maximum current watcher, please download the following data sheet / instructions

Maximum Current Monitor – Instructions- for electric central heating boilers from Flexiheat UK

What are my other options? Well the best solution would be to get your electrical supply upgraded to Three Phase – Is it possible / How much is it to do this? I don’t know , we just supply the boilers – please contact UK Power Network , who are responsible for this here

Or another option may be to get a second 100 Amp supply to your property – Again , contact UK Power Network on the link above – this option may well work out cheaper than having three phase supplied to your property.

This system is used on our electric boilers – please see this webpage –