E7 Water Heater

MickeyD

I just moved into a new apartment and it has one of these dealies for heating the water http://www.adverts.ie/fixtures-fittings/horstmann-water-heating-control-quartz-e7/333618

Anyone familiar with how it works? The timer dial is a bit unintuitive, I don't see a way of setting how long the water heater comes on for and when, so I turned it off for now.

So far I've been using the boost for about 30-40 min (roughly, the boost dial has no markings) to heat the water for a shower but if I could get it to heat the water for say an hour off peak for when i get up then that would be a lot better. I don't want it heating for more than that though or it'll be a waste.

Pete67

The timer is preset to provide water heating using the night rate, as long as you make sure that the correct time is showing against the summer/winter time marks on the main dial on the left hand side. Just leave the main switch set to Auto and it will take care of itself.

The thermostats in the immersion heater(s) will switch them off once the water is hot enough. As long as the hot water cylinder is well insulated then it will not lose much heat during the day so unless you are using loads of hot water you should not need to use the boost.

The timer on/off times can be set by opening up the unit if necessary, but the standard times set up by the installer should be OK for nearly every situation.

If you use the Boost during the day it will cost nearly twice as much to heat water when compared to the night rate.

MickeyD

aye i realize its more expensive to use it during the day, but if the timer is set to heat it for 2 hours off peak and i heat it 30 mins peak, then it would still be cheaper.

Pete67

The idea with these controllers is that the cylinder is VERY well insulated and does not lose much heat over time. All hot water is normally heated at the night rate, and is therefore cheaper. Once hot, even if the timer is on for several hours at night, the heaters will switch off anyway to avoid overheating and boiling the hot water cylinder. So you only use enough electricity to replace the amount of hot water used plus a small amount for losses. You are better off doing this on the much cheaper night rate. Hope that makes sense.

Some hot water cylinders have two heaters, if you really want to avoid heating and storing lots of hot water then you can disconnect the lower heater, or just turn the its thermostat as low as it can go. Only the water above the top heating element will then be heated, which might be enough if you do not use a lot of hot water. If it's a combined bath/sink immersion (less common on GoldShield installations) then leave the bath/sink switch on sink.

I'd make sure the time is set correctly on the controller and leave it on automatic and you will always get the benefit of the night rate electricity.

MickeyD

there's no lagging jacket on the boiler here and the top is just a lid that comes off and doesn't fit right. I think ill just stick to the 30 mins boost, its the same as what a power shower would be anyway.

Cmar-Ireland

I was looking at fitting one of these timers to our immersion. Reading the install guide it seems like the minimum 'on' period is 4.5hours. Does this seem like a long time? I would have thought 2hours would be enough?

deepspeed

In my mate's apartment, we replaced the old manual E7 unit that the OP mentioned with a digital one from these guys:

http://www.tlc-direct.co.uk/Products/HOELEC7.html

It was around €80 delivered.

Easy as pie to fit, and the digital timer can be set as you like. We set it so that it comes on at 4am and off and 4:40am. This is plenty for their use (2 people).

The unit is very flexible and can accomodate 4 different on/off programs as well as a few boost programs and, like the old analog model, you can press the "boost" button and it comes on for a preset time.