Horstmann Economy7 Quartz - timed heating not working

[arekzmier]

Hi everyone, long-time lurker but first-time poster here.

I need some help with my immersion heater, please.

I have a Horstmann Economy7 Quartz timer feeding a Heatre Sadia Megaflo dual element immersion heater.
Water is not being heated in the 'TIMED' mode - the light does not come on at any point - I turned the dial to check. The clock is working. The 'BOOST' mode heats the water fine (light comes on as expected).

The whole setup has worked well for the last 4-5 years (only had to change the heating element once).

I suspect the problem is with the timer itself? Any other ideas?

If it is the timer - can I get some other setup installed? Economy 7 is no longer a thing as far as I know, what other options are there? Is a timer needed at all? Wouldn't two separate on/off switches kind of do the same thing?

Thanks!

[Someone-Else]

What light does not come on? (You are there, I am not)
A timer is used so that the heater only comes on at "cheap rate" if you had just a switch (or two) you would by human nature, leave one or both switches on when they shouldn't be. (Say when you are out for the day, yes the thermostats would turn them off, eventually, but you would be heating water when there is no need)

[ericmark]

As said Economy 7 is a tariff not a system, I have a EV tariff, similar but only for 5 hours not 7. However the old Economy 7 used a white meter, and there was a different fuse box for off peak items, but this did not allow one to use other items like washing machine, tumble drier, and dish washer on off peak tariff, so latter the wiring was combined, and one had a trigger signal, in the main it used a signal from radio 4 long wave, but this is due to be turned off, seems the valves are no longer made, so BBC has said when the valve fails they will turn the transmitter off. So there has been a role out of so called smart meters to replace the old system.

The originally timer had two supplies, but latter versions went to a single supply, and although they existed I have not worked on one. For my installation the off peak charges a battery 3.2 kWh and this keeps the house running until the sun comes up. Which means I can use all items at normally until the sun goes down. If I have not set the dish washer off in the day, then I set it to run after 1 am summer midnight winter, same with washing machine and tumble drier.

My immersion heater has a CT coil and only switches on when it detects I am exporting power to the grid. Winter central heating heats water.

I have a lovely tool,

Testing for live.jpg (82.7 KiB) Viewed 648 times

which allows me to test for voltage with no contact, but the question is what have you got to test with? You may find the instructions for the timer on the internet, yes there are simple switches check this link https://www.tlc-direct.co.uk/Products/M ... 8OEALw_wcB

[aeromech3]

So to be clear, the water does not heat even when the timer clock is set to differing times and the timed amber light does not come on correct?
Turning the Boost knob, its light comes on and the water gets hot?
I am not familiar with the internals of the Eco 7, but it would appear that there are two switches (aside from water heater Off) and the timer one has failed.
You have to look at what standard deals are available before cancelling eco7, as if you use other high consumers like washing/drying machines or storage heaters during the cheap rate now, you might loose out.
If you decide to change to a simple on/off switch you have to time it yourself to coincide with cheap rate eco7 and might just as well stay with the Boost facility, at least it will not stay on permanently if you forget to switch off.

[arekzmier]

Thanks for the replies.

Yes, that's correct - boost works as expected, amber light comes on. The timer moves, the clock ticks etc, but the amber light never comes on and water is not being heated in timed mode. All worked fine up until 2 days ago.
Could it be anything else other than the timer being faulty?

There is no 'cheap rate' - I pay the same rate regardless of time of day. I've never had a contract with an Economy7 tariff and it was never an option when signing on with an energy supplier.

[aeromech3]

Could it be anything else other than the timer being faulty?

Part likely Not, if only one supply is going into the timer and not a separate one for if eco7 was available. Explanation: some set ups the Boost connects to one element usually top and the Timer to the other, without checking for this one cannot say if the timer element has failed!
Now if common (one) power is going into the timer, confirmed by clock works as does boost setting; if the internal switch for the Timer has failed, burnt, it could be due the element it is connected to, has failed
If you have two supplies into the timer then you need to check the FCU's, even if the clock works it might be designed to use the normal supply, as the ECO7 in some set ups is only available during the 7 hours, and the clock has to be powered continuously.
As stated don't know the internals but this would be one set up:
Terminal 1 = Live Feed In
Terminal 2 = Neutral Feed In
Terminal 3 = Common Immersion Neutrals
Terminal 4 = Live BOOST Feed to Immersion (top unit)
Terminal 5 = Live OFF PEAK Feed to Immersion (Bottom Unit)
And usually only one element can be powered at one time, not together!

[peter c]

Some years ago I had a similar problem when my dual element immersion heater packed up. The old Horstmann non electronic timer was basically "goosed" when the immersion packed up. Like yours it would only work manually. In the end I replaced the old timer with a new Horstmann electronic timer which unfortunately was not very reliable. After a couple of years having got fed up with tepid showers I replaced the Horstmann with a Sangamo timer (which incidentally was cheaper than the Horstmann at the time). This works perfectly moving the hour across at GMT and BST. I have no connection with either Horstmann nor Sangamo.

HTH
Peter C

[ericmark]

If no off peak, why have a timer? I find when using central heating boiler which has no tank thermostat connected to it, I need it timed so the pipes between the tank and the boiler are not kept hot. This is clearly not a problem with an immersion heater, I also found the tank will stay hot with the amount of water we use for two days, so I set central heating boiler to run four times a week for half an hour each slot, of which it actually run for 20 minutes before the return water temp turned boiler off.

It would be interesting to see if having a full tank costs any more to having just the top hot with modern insulation, however as far as I can see only reason for heating just the top, is it gets hot quicker, google Eco 7 immersion heater timer and it seems plenty still made, so could fit new, as to off peak, when on single rate it was 29.57p / kWh and 62.21p standing charge, when I moved to EV tariff it was 8.95p off peak / kWh and 31.31p on peak with 59.14p standing charge. We use around 17 kWh per day, so if all used at peak rate having the off peak would cost 26p per day extra. But we have washing machine, tumble drier, and dish washer with built in timers, so can be set to run on cheap rate. And most the day time power used is from solar and the battery, so of the 17 kWh we use, only 8 kWh comes from the grid, and of that 8 kWh most comes in at off peak rate.

So we had iboost+ fitted, which in hind sight was a mistake, it powers the immersion heater when we have excess solar, however the export rate for solar is over the off peak rate so once we get export sorted out, it would be cheaper to heat water with a timer.

Our 3.2 kWh it not quite large enough to ensure we only use off peak, but the amount of on peak power is very small, batteries have a limited life, so looking at pay back in 7 years or not worth having, and so second one not really worth it for us, we can have up to 4 batteries.

I say all this as you may in the future decide on solar or batteries, and to get rid of the timer then latter replace is counter productive, so even when at the moment just bottom element with no time may seem best option, this may change in the future.

Storing hot water is cheaper than storing chemical energy in the form of batteries, so one does need to look to the future and what you may fit.