I have a Horstmann Economy 7 Immersion Heating Timer for my electric
hot water tank. It hasn't been used for a long time and now the timer
will not work (neither the booster or the normal 24 hour dial).

Is it easy enough to remove the cover and replace the battery (and if
so, what type) or do I have to buy a new one? If a new one is
required, I would be grateful for recommendations on more 'up-to-date'
timers. My boiler has two elements (night rate and booster).

Also, I'm confused as to how the battery recharged. According to the
installation guide, the batter is recharged as long as there is power
to the box:
http://www.horstmann.co.uk/downloads...structions.pdf.
Although I don't frequently use the timer (the power button is usually
set to off), I did not cut off the electricity supply. So if I were to
turn the booster, the heater would still work (even though the booster
timer doesn't progress through the hour). Does this count as having a
constant supply of electricity to the box so that it stays recharged?

On 3 Jan 2007 13:21:53 -0800, AmyGG wrote:

So if I were to turn the booster, the heater would still work (even
though the booster timer doesn't progress through the hour). Does this
count as having a constant supply of electricity to the box so that it
stays recharged?

I would think so, I'd expect the battery charging circuit to be connected
in parallel with the clock motor. The fault might be the battery but it
could equally be the clock motor, so you could spend time and money
replacing the battery and still not have a working device. Basic
electronic disgnostics would help, has the battery got the correct
terminal voltage, does the motor get power etc

If you don't have those skills it may be better to bite the bullet and
get a new one with a digital (non-mechanical) clock they aren't
particulary cheap though (approx £50).

--
Cheers
Dave. pam is missing e-mail

Dave Liquorice wrote:
On 3 Jan 2007 13:21:53 -0800, AmyGG wrote:

So if I were to turn the booster, the heater would still work (even
though the booster timer doesn't progress through the hour). Does this
count as having a constant supply of electricity to the box so that it
stays recharged?

I would think so, I'd expect the battery charging circuit to be connected
in parallel with the clock motor. The fault might be the battery but it
could equally be the clock motor, so you could spend time and money
replacing the battery and still not have a working device. Basic
electronic disgnostics would help, has the battery got the correct
terminal voltage, does the motor get power etc

If you don't have those skills it may be better to bite the bullet and
get a new one with a digital (non-mechanical) clock they aren't
particulary cheap though (approx £50).

Both the clock and the booster clocks are not working. They used to
work but I stopped using it for several months and I did not make any
adjustments to the electrics during this time.

On 4 Jan 2007 16:56:11 -0800, AmyGG wrote:

Both the clock and the booster clocks are not working.

Almost certainly driven from the same motor. But as installation
instructions say the clock won't run until power has been applied for
about 15 minutes to charge the battery it's difficult to say if the
failure is due to the motor or the battery.

They used to work but I stopped using it for several months and I did
not make any adjustments to the electrics during this time.

Either take it apart and do the basic electronics diagnosis or replace
it:

http://www.tlc-direct.co.uk/Products/HOELEC7.html £56.95
http://www.tlc-direct.co.uk/Products/HOE7Q.html £56.85

For 10p I'd go for the electronic one. Constantly running mechanisms will
always wear out and/or break.

--
Cheers
Dave. pam is missing e-mail

In message om, Dave
Liquorice writes
On 4 Jan 2007 16:56:11 -0800, AmyGG wrote:

Both the clock and the booster clocks are not working.

Almost certainly driven from the same motor. But as installation
instructions say the clock won't run until power has been applied for
about 15 minutes to charge the battery it's difficult to say if the
failure is due to the motor or the battery.

They used to work but I stopped using it for several months and I did
not make any adjustments to the electrics during this time.

Either take it apart and do the basic electronics diagnosis or replace
it:

http://www.tlc-direct.co.uk/Products/HOELEC7.html £56.95
http://www.tlc-direct.co.uk/Products/HOE7Q.html £56.85

For 10p I'd go for the electronic one. Constantly running mechanisms will
always wear out and/or break.

And electronic ones have batteries which die, caps which dry out, zeners
which go soft etc ...

Swings and roundabouts, innit

but yes, electronic



--
geoff