How do I operate Santon Unvented Hot Water System, model PP170E?

[Himanshu]

How do I operate Santon Premier Plus Unvented Hot Water System, model PP170E? I recently moved into this rented, all electric, 2 bedroom flat. I am spending more than £10 per day at the moment, which is simply unaffordable. There are two switches - cables connected to the a thermostat housing, one on top (i think this is called booster), and one to the thermostat housing in the lower half. Both the switches are in the on position. The one connected to the booster element also has a small panel in it for the fuse. The thermostat both have a scale of 1 to 5, and in both cases they are set just less than 4.

We are a family of 3. We generally need hot water in the morning for showers, and a quick one in the night. If so, can I simply switch off boilers through the day, and switch them on an hour or so before the showers? Would that help, or would it cost as much because water would have to be heated from cold every time we switch it on? Or is there something wrong with the boiler causing high bills? I don’t see any leaks, or any obvious issues.

Am a complete noob and do not understand anything about boilers. I have scoured the manual, but don’t see any explanation of how the booster works, and if there is an optimal way to use it.

 

[Basher]

With all electric hot water, I would normally expect an immersion heater controller to be fitted, which would switch on the immersion heater for a period before you need the hot water.
The boost heater at the top of your cylinder is to switch on if you run our of hot water, as it heats just the top of the tank, and doesn't take so long to heat. It is NOT normally left on.
The heater at the bottom heats all the tank. It should take about 2.5 to 3 hours to heat a cold tank.

Often electrically heated cylinders are used on an 'Economy 7' electricity supply, where the electricity at night is cheaper, so you have your hot water heated at night on cheap electricity, ready for the day ahead. If you need more than the tank full, you switch on the boost when needed.

You need to find out if your electricity supply is "dual tariff", ie cheap at night, expensive during the day.
If it is, the reason you are paying so much is that you have the boost immersion on all the time - so switch it Off and only switch it on if really needed!

If you are not on a "dual tariff", you will be paying around 50p for every hour one immersion is heating.

Your idea of switching on a while before you need hot water will help. I'm surprised there is no time switch there to do this for you. It will take 2 or 3 hours to heat the tank from cold, but hopefully it won't need heating fully.

it might be useful to chat to your neighbours to find out how they manage their hot water controls!

As a guide, just heating your tank so it's full (about 140L) of hot should cost £1.50. Either you have electric heating as well, or you are using a lot of hot water!

 

[Himanshu]

If you are not on a "dual tariff", you will be paying around 50p for every hour one immersion is heating.


As a guide, just heating your tank so it's full (about 140L) of hot should cost £1.50. Either you have electric heating as well, or you are using a lot of hot water!

Many thanks for the detailed response. I do have electric heating - underfloor. I am using that only for 1 hour a day. And my house is pretty cold through the evening. But I am powering through that.

I don't think I have Economy-7 meter. But based on what I have read of it, that's useful only if i am storing heat through the night. The only thing I have that stores heat is The unvented heater. So not sure if economy-7 is useful for me. Regardless, neither is Bulb (my current supplier) offering it right now, and when i try to use uswitch or some other service to compare other providers, they don't give any results as better options.

I woke up today with my meter already reading £3.5 at 6.45 in the morning. Which correlates perfectly to 50p per hour you said. I did keep the booster off last night, but it doesn't seem to help. I guess, next step is to keep the water heater off through the night and switch it on just before the shower in the morning.

If I keep the water heater on for 2-3 hours in the night, would the water be still somewhat hot in the morning, so the heater is not heating freezing water in the morning. Net-net, maybe if my water heater is working only 5-6 hours through the day, maybe it will help reduce the bills

 

[Basher]

I think you are right, with electric heating needed during the day, Economy 7 would not help.

Your hot water cylinder is well insulated, so if you heat it for a couple of hours or so, it should retain the heat to an acceptable level for most of the day.
As an example, I have a 200L cylinder, and it is switched on by a timeswitch at 6.00am and 6.00pm, but only consumes electricity for between 30 to 60 minutes each time, but we don't use a huge amount of hot water.

If your cylinder is consuming power all night, either you are using a lot of water, or (if it's an unvented cylinder, mains pressure), there may be a fault where water is being released by the over-pressure valve and running to the drain. If you can hear or see water trickling, it would be worth getting it checked out.

Heating the cylinder should not take all night. If you have used all the hot, re-heating it should not take longer than say 3 hours, and then the electricity consumption should pretty well stop (ie say total £1.50). So either other appliances are using power, or there is something wrong.

It would be worth experimenting with turning it on only at certain times. You could fit a time switch to do this for you!