URGENT Santon PremierPlus unvented boiler - super high bills

[joshuab]

Disclaimer: I know very little about boilers so sorry if my assumptions are way off! From testing by logging energy usage, and that if I turn the boiler on the meter lights up like a Christmas tree, it seems our Santon PremierPlus boiler (PP170E) is constantly running causing extreme energy usage/bills.

First things first - we seem to have a leak from the boiler. I've contacted our landlord and hoping for someone to be sent round to look at that ASAP but it's proving to be a little slow process....

We have 2 switches next to the boiler, one is a fuse box with a timer and the other is just a normal switch. The normal switch is what we are currently using to generate hot water, and with the fuse box, leaving it on for extended periods of time does not seem to heat any water (it just turns the lights on for the underfloor heating).

Here is an image of the switches: https://i.*********/SsPBsia.jpeg

I had a look over the schematics in the manual of the boiler and I can see that there is a boost element. Our switch has a cable which goes into the area shown on the schematic. Schematic seen on page 8 (FIG. 5) of this manual: https://www.advancedwater.co.uk/STOMEMO/A540-088-1501/Santon Premier Plus Installation Guide.pdf

Here is an image of our boiler and the cable going into it: https://i.*********/XNFmdNt.jpg

So would I be right in saying that we have been using the booster to get the boiler running all this time?
If yes for the above question I then wonder if the water leak is stopping the usual way the boiler is meant to heat up the water (ie with the fusebox with the timer)?
And that if the water leak is affecting the component that detects it doesn't need to heat the water anymore?

I'm hoping to know more in an attempt to convince landlord to send a boiler specialist (at the moment I'm having to manually turn on the boiler by the switch when I wake up, wait for a while, take a shower, remember to turn it off - which is less feasible when my house mates get here (am a student)).

Huge thanks in advance

 

[gmartine]

Hi

Firstly I can't seem to access the images.

Secondly what you're referring to is an unvented hot water (HW) cylinder or heater not a boiler so it is probably providing all your HW needs.

Your HW cylinder has two heating elements, (upper and lower) where the timer should be connected to the lower (to heat all the cylinder) where you should only use the "boost" switch to heat the upper element when quick access to HW is required.

If you have no gas boiler, you should be using the timer to heat the HW cylinder (lower heating element) at night on an economy 7 tariff so it can provide you with HW for the day while paying the least possible for it.

The leak maybe connected to timer circuit not working, either way you need to get someone in to check it and get it working or at least show you how.

 

[Chuck]

If the leak is leaking hot water it will increase your electricity consumption.

The system should be controlled by a time switch.

All water heaters will use a lot of electricity when first turned on as they heat the contents of the cylinder. Once it is up to temperature the thermostat should start operating and cut the (average) consumption.

You really need to record your electricity consumption and amount of hot water you use over a typical 24 hour day so see where you stand.

Using electricity for heating is going to be very expensive. It's why gas boilers are so common. If you want to keep the bills affordable, get used to taking short or cold showers!

 

[joshuab]

Hi

Firstly I can't seem to access the images.

Secondly what you're referring to is an unvented hot water (HW) cylinder or heater not a boiler so it is probably providing all your HW needs.

Your HW cylinder has two heating elements, (upper and lower) where the timer should be connected to the lower (to heat all the cylinder) where you should only use the "boost" switch to heat the upper element when quick access to HW is required.

If you have no gas boiler, you should be using the timer to heat the HW cylinder (lower heating element) at night on an economy 7 tariff so it can provide you with HW for the day while paying the least possible for it.

The leak maybe connected to timer circuit not working, either way you need to get someone in to check it and get it working or at least show you how.

There was a change of mind by the landlord since I typed up this post (I posted a few days ago but my account just got approved today) and a boiler technician was sent out for an inspection. He explained to me that nothing was connected to the lower heater. Only the boost was connected and that's what we've been using to heat water and the timer is just for the central heating (he opened the fuse box and it wasn't connected to make sure it wasn't connected to the switch).....

It also explains why we always run out of hot water really quick, if it's only warming the top half!

The leak is still uncertain as the boiler technician said a plumber is needed for anything related to that.

The visit by the boiler technician was just an inspection so nothing has changed as of yet, but I think, if landlord approves, the switch will be connected to the lower heater rather than the upper and will also be connected to the timer. He did mention though it might of been done like this because something might of happened to the lower heater - which hopefully isn't the case!

Thanks to all responses!

 

[joshuab]

If the leak is leaking hot water it will increase your electricity consumption.

The system should be controlled by a time switch.

All water heaters will use a lot of electricity when first turned on as they heat the contents of the cylinder. Once it is up to temperature the thermostat should start operating and cut the (average) consumption.

You really need to record your electricity consumption and amount of hot water you use over a typical 24 hour day so see where you stand.

Using electricity for heating is going to be very expensive. It's why gas boilers are so common. If you want to keep the bills affordable, get used to taking short or cold showers!

Sadly it turns out currently we don't seem to have the luxury of a timer!

For electricity usage - with the water heater on over a 24 hour period it cost £13.82. Most recently we had a stretch over 16 days which cost £186.95 (1113 kWh) - where 4 of those days the property was vacant! Soon as I turned the water heater off for a 24 hour period, usage dropped to £1.12.

Because of such the high usage I believe it's just constantly trying to heat the water no mater it's current temperature (I wonder if that means the internal thermostat for the booster is dead? if it even has one?) - this wasn't discussed however when the boiler technician visited for inspection.

 

[Timmy D]

You mention a leak?
Am I correct in assuming the leak is water running through the tundish (black plastic thing on the vertical pipe to the right of the cylinder)?
If so, the safety valve has activated.
Is the leak quite high flow?

Your reported kw usage over 16 days is pretty much spot on with what the total would be if the 3kw immersion was running 24 hours a day for 16 days.

If the leak is at the tundish and at a flow similar to your bathroom tap, your hot water is going down the drain and you keep reheating new cold. This would explain the immersion being on 24/7.

You need to solve the safety discharge issue. You need a g3 qualified plumber to investigate and fix the discharge.

Then you need a timer to heat the cylinder up at night.

 

[Chuck]

For electricity usage - with the water heater on over a 24 hour period it cost £13.82. Most recently we had a stretch over 16 days which cost £186.95 (1113 kWh) - where 4 of those days the property was vacant! Soon as I turned the water heater off for a 24 hour period, usage dropped to £1.12.

So, over the 24 hour period it used

(£13.82-£1.12) * 1113 kW hr / £186.95 = 75.6 kW hr.

That means the heater has been drawing 3.2 kW, i.e. full power, continuously. That's enough to heat cold water from 10°C to 60°C at a rate of

3200 J/s * 60 s/min / ( 4200 J/kg°C * (60°C - 10°C ) ) * 1 litre/kg = 0.91 litre/min.

Looking at the picture, it looks as though the pressure/temperature relief valve is discharging. This may be the root cause but it is more likely that either the heater thermostat has failed, in which case the hot water will be dangerously hot, ca 90°C, or the pressure regulation valve is faulty and over-pressuring the cylinder.

In any of the above scenarios, the heater needs to be switched off and a G3 (unvented hot water systems) qualified plumber or heating engineer called to fix the problem(s).

Unvented systems must be serviced annually. They are downright dangerous if they are not working properly.

 

[ShaunCorbs]

Also the boiler technician or anyone can’t touch the cylinder or wiring unless there g3 (unvented) qualified and registered

 

[joshuab]

Ah....

I'm not 100% sure of the source of the leak - but it's most probably as you say. I've never heard any water running or dripping in the cupboard (excluding the 2 times I'm about to mention) but the carpet is always soaked corner to corner.

Twice however we have caught it releasing water via the 'tundish'.

The first time it was stopped by twisting the black valve (in the middle of the boiler) clockwise for 10 seconds or so. This was about a month ago.

The 2nd time it stopped on its own after a while. This was a week ago.

I believe both times were after it hadn't been on for week/s however (as we aren't at the property much currently due to COVID) and we had come back to see it doing this.

Video of first time: Video of second time:
Here is also a higher res image of the tundish - but yeah, it looks like it's quite a bit of action...:

I will enquire about the boiler technician's qualifications (in a way that doesn't sound like I'm being rude ). In relation to servicing - they landlord owner purchased the property a couple months before we started renting (6 months ago ish) and I have no idea if it was serviced or checked then. The markings on the boiler itself indicate it was installed on 04/04 (2004?) but that's all. I will avoid using it and hope I hear something back from the landlord soon (nothing mentioned since the inspection or about the inspection yet).

And as estimated by a poster, it's indeed a 2.7/3kWh heater!

(I removed a couple things for data protection, just in case!)

Once again huge thanks to all responses!

 

[joshuab]

Ah.***

I'm not 100% sure of the source of the leak - but it's most probably as you say. I've never heard any water running or dripping in the cupboard (excluding the 2 times I'm about to mention) but the carpet is always soaked corner to corner.

Twice however we have caught it releasing water via the 'tundish'.

The first time it was stopped by twisting the black valve (in the middle of the boiler) clockwise for 10 seconds or so. This was about a month ago.

The 2nd time it stopped on its own after a while. This was a week ago.

I believe both times were after it hadn't been on for week/s however (as we aren't at the property much currently due to COVID) and we had come back to see it doing this.

Video of first time: Video of second time:
Here is also a higher res image of the tundish - but yeah, it looks like it's quite a bit of action...:

View attachment 61343

I will enquire about the boiler technician's qualifications (in a way that doesn't sound like I'm being rude ). In relation to servicing - they landlord owner purchased the property a couple months before we started renting (6 months ago ish) and I have no idea if it was serviced or checked then. The markings on the boiler itself indicate it was installed on 04/04 (2004?) but that's all. I will avoid using it and hope I hear something back from the landlord soon (nothing mentioned since the inspection or about the inspection yet).

And as estimated by a poster, it's indeed a 2.7/3kWh heater!

View attachment 61346
(I removed a couple things for data protection, just in case!)

Once again huge thanks to all responses!

Just a minor correction, the 2nd time it stopped releasing water via the tundish was some hours after the water heater being turned on (it was off for a couple weeks). In hindsight - probably not a great idea!

 

[gpbeck]

This is potentially dangerous and your Landlord/agent has a duty to you to resolve it as an emergency. Until then it should be kept turned off, which leaves you without hot water, another duty the Landlord has.