OSO hotwater boiler_Issue heating the water

[Nicole_]

I currently rent a flat, which uses an OSO hotwater boiler to heat the water but it seems there is an issue heating the water and I thought to ask here in case anyone would have an answer before I ask my landlady to call an electrician.

Attached is an image of the boiler on Pic1 and on Pic2 is the switch with a timer (in red circle) which is linked to the boiler.

The issue is that whenever I take a shower and use all the hot water then there is no hot water until the next day. I asked the concierge in the building and they told me I need to move the switch of the timer to the “permanent” position so the boiler can heat the water instantly.

It’s been a week since I did this, but it seems the issue still persists. For example, the other day I took a shower at 1pm and used all the hot water. I then went to take another shower at 10pm and there was no hot water. There was enough time in between for the boiler to heat the water, but that didn’t happen.

Does anyone know why is this happening?

 

[marconi]

Yes. I will study it now.

 

[marconi]

Nicole - I think any further advice from me will have to await the repair by the plumber using the parts on order: do you have a return date?

Once this is done you need to confirm with him which element he has left connected to the timer which is to the left of the Delta Dore controller labelled 'Heating'.

Then we need to have another discussion including changing your tariff to one which includes periods of cheap electricity if your usage of space and water heating suits those on offer/available to you.

Is your flat similar to others in the block? If your flat's design for water and space heating is repeated in neighbouring flats it would be helpful to see some pictures of their electrical equipment ie the sort of pictures you have provided me already.

Is this fine with you for now? Do say if not.

 

[Nicole_]

Well, I'm confused to be honest I worry if the plumber makes things worse and end up without hot water at all.

How is it possible that after he changed the parts it worked for a day and then the next day nothing? That's what I don't understand. What could that mean?

I just feel that if I don't understand a little bit what is happening then I don't know if I can understand whether he knows what he is doing or not.

Could it be a problem with the switches and not the water tank at all?

 

[nicebutdim]

Well, I'm confused to be honest I worry if the plumber makes things worse and end up without hot water at all.

How is it possible that after he changed the parts it worked for a day and then the next day nothing? That's what I don't understand. What could that mean?

I just feel that if I don't understand a little bit what is happening then I don't know if I can understand whether he knows what he is doing or not.

Could it be a problem with the switches and not the water tank at all?

While anything is possible (almost), I'd advise continuing with the investigative process started by @marconi

He seems to be working methodically through the possibilities and providing the information requested will result in a thorough analysis of the problem. Granted this may not be as fast as a visit from a local spark, but his help here isn't being charged at an hourly rate.

 

[marconi]

Nicole: Thank you for your last post. You are clearly exasperated and who wouldn't be. I'll explain what I think is the situation at the moment.

1. Your flat relies on electricity for space and water heating. To be most economic you need to be on a dual rate electricity tariff such as Economy 7 or Economy 10. These provide periods of cheaper rate electricity. Time switches are used to turn the space heating and water heating on and off to utilise the cheaper rate periods. At the moment you do not have a dual rate tariff. I believe you 'lost' a dual rate tariff when you swapped from the pre-payment meter to a credit meter with British Gas.

2. Your hot water tank has two elements, the bottom one to use cheaper rate electricity and the top one as a boost using whatever tariff is operating when it is on. What I cannot know now is whether the time switch to the left of the Delta Dore controller was for the bottom element to switch it on during cheap rate; the top element being then simply controlled manually by the left hand 'Water Heater' switch - you'd have to remember to turn it on and off.

3. I reckon though that the time switch to the left of the Delta Dore is for the top element as it is used now. The bottom element was then being switched on and off for the cheap rate by the old prepayment meter. There is a hint to this set up by the thinner brown grey vertical wire going into the brown plastic box with 'PROTEUS' written on it. I believe it previously went into your old prepayment meter. But since your change to a credit meter, which does not have an output which switches on and off during cheap rate, it has been connected to the brown box which now provides a permanently on supply for the bottom element. The bottom element is now only being controlled manually by the right hand 'Night Immersion Heater' switch. Thus, the change from prepayment to credit meter has resulted in no time control of the bottom element meaning it has been on constantly albeit regulated in temperature by its thermostat. Meter change men/women are not obliged to ensure any downstream effects of the meter change are attended to. So since your meter change I believe - perhaps you can confirm from experience - the top element has been controlled on/off by the time switch left of the Delta Dora and the bottom element has been on permanently if its switch is on.

4. Now, I may not have the full history of this panel correct because one can see a square white plastic blank fitting bottom left below the 'Immersion Heater' switch. It may have once had a square timer here which looks like this:

Electrisaver Immersion Heater Booster - https://www.tlc-direct.co.uk/Main_Index/Water_Heating_Index/Immersion_Heater_Timers_2/index.html

or this

24 Hour GP/Immersion Heater Timeswitch - Flush/Surface | Timeguard (NTT01) - https://www.tlc-direct.co.uk/Products/SMNTT01.html

These would control the top element. The timer to the left of the Delta Dora would then do the bottom element.

5. With me so far? ;-)

6. Good. You told me that you had never seen the right hand 'Night Immersion Heater' switch orange light on when the switch is on. This is odd because now, since the credit meter, it has a permanent supply all day long via the red switch and the 16A circuit breaker on the far right of the consumer unit and it is clear from the photo that these two switches are both on - they in the up position. This indicates that the supply has been disconnected somewhere at or before the 'Night Immersion Heater' switch. This begs the question why would someone do this?

7. I suspect - cannot know for certain - the plumber has disconnected the supply to the bottom element because he found it defective. The spare on order would be the replacement element. He may have temporarily connected the top element to the timer to the left of the Delta Dora to the top element or it may have been always so.

8. I cannot investigate the disconnected supply because it would require live electrical equipment to be opened up. This is why I said we must wait for the plumber to return and finish his work and I asked you to clarify with him how the top and bottom elements have been connected.

9. When we have two working elements we can discuss dual rate tariffs which depending on your lifestyle and electricity use profile may be more economical. You could have a read of these in the meantime from which you will learn about E7 and E10 and some other tariffs.

What is an Economy 7 meter? | Understanding Economy 7 - https://www.uswitch.com/gas-electricity/guides/economy-7/

What is Economy 10? A complete guide to Economy 10 meters and tariffs - https://www.uswitch.com/gas-electricity/guides/economy-10/

7 facts about Economy 7 meters, tariff and times - https://www.edfenergy.com/energywise/all-you-need-know-about-economy-7

10. I hope this provides some clarification. The most important thing to say is that as a tenant your landlord is responsible for fixing this problem in a timely fashion using qualified contractors. It is reasonable to wait say a week maybe two weeks at most for spare parts but any longer it is not. How long ago since the plumber visited?

11. I have sent you my mobile number if you want to call me. If I don't answer straight away leave a message or send me a text/whatsapp.

PS: Re your #6 - it looks like the top element white wire goes into the timer and the bottom element white wire goes into the white plastic trunking - is this still the case?

 

[marconi]

Well, I'm confused to be honest I worry if the plumber makes things worse and end up without hot water at all.

How is it possible that after he changed the parts it worked for a day and then the next day nothing? That's what I don't understand. What could that mean?

Please describe in more detail if you can.

I just feel that if I don't understand a little bit what is happening then I don't know if I can understand whether he knows what he is doing or not.

Could it be a problem with the switches and not the water tank at all?

Yes it could be a problem with switches or their connections but at the moment I reckon not.

 

[marconi]

Nicole_ Hello. I wondered if you had an update?

 

[Nicole_]

Hi, I've been meaning to give an update but I've been so busy with life and frustrated with this water heater situation that I didn't want to think about it anymore. I cannot believe that basically it took us 3.5 weeks since the issue started and the issue is still there. I'm only a tenant and shouldn't really been bothering with all this, but my landlady does try to be honest.

So, basically the plumber came on Saturday and changed both immersion heaters and the thermostats. Photo attached. He said that he changed everything that he could on the cylinder and if there are still issues then an electrician needs to have a look.

Again, if I switch on the "Water heater" it works for one hour and then it stops. If I switch on the "Night Immersion" it works only if you sort of play with it a little bit which I'm scared to even touch.

Would you think that an electrician needs to come and have a look at the switches? Like all this time maybe the issue was with that?

If it was up to me, I would have just replaced the cylinder to begin with.

I'm just conscious if these people are just lying so they can take the money knowing that the issue cannot be resolved.

 

[marconi]

Thank you. I will reply today Tue 28 Mar 23.

 

[marconi]

From what you said in your last message it looks like the Night Immersion Switch is faulty or there is a loose connection. When you played with the night immersion switch did the orange light illuminate?

 

[marconi]

Do the hands of the Grasslin timer switch show the correct time?

At the moment the picture you sent of it shows it on in these periods when timer mode is selected and the correct time is set on the hands:

1000-1200

1800-2030

2130-2230

2330-2400

(You may have changed these times in which case please send me a new photo).

Does the vertical cable from it still go to the top element?

For the timer to keep the correct time the left hand water heater switch must be left on. You can then use the three position slider switch near the hands to control the top heater, the three positions being timed mode, off and permanently on.

 

[marconi]

Nicole_ I hope you are just busy and not that you are tired of all my questions ;-)

I want to give you some questions for an electrician to answer once he/she has visited and inspected what's what - because there will need to be a visit paid for by your landlady. But just need a little more information first. We can bowl out the tank and its heaters now as the problem.

There are female electricians if you would prefer one to visit. We can also see if a trusted forum member is near by.

 

[Nicole_]

Hi marconi! Sorry I didn’t reply, I was just busy. Thanks again for all the info though. So to answer the questions.

Night Immersion- The orange light doesn’t illuminate. It actually goes on and off. Like it’s flashing sometimes. But, the majority of the time it’s off.

Grasslin timer- I changed the times today because my landlady asked me to do so to check if it’s going to work. I did but still it doesn't work. Just to say again though, that this timer I have it on the permanent position which means that it doesn’t matter anyway what times I put there. If a photo is still needed then let me know.

Vertical cable- I don’t know exactly where it goes to because they get mixed under that white thing and then I don’t know where it ends up.

Electrician- My landlady said she has asked the plumber to bring an electrician. But, yes if there is a trusted forum member I could consider and pass the info to the landlady.

What questions would you recommend asking the electrician?

 

[marconi]

What is your district in Liverpool so I can make some enquiries about forum electricians in your area?

The items I have highlighted in bold are what you need to address with the electrician.

The flashing orange light is not right. Please leave that switch turned off for now. It needs an electrician to investigate.

If the hands of the Grasslin timer are not moving and keeping correct time then it is duff and requires replacement. But as you say in constant on mode that provides power to the immersion top heater controlled by the left hand switch. But you only heat the volume of water above the heater as heat rises. To keep the correct time it needs the left hand switch to be left on - is this what you have done?

Your installation is lacking a way of turning the bottom element on and off to match off peak electricity rates. An electrician will have to provide another time switch for the bottom element. See my recommendation at the end.

You are on the wrong type of tariff for electric water and space heating because you have no periods of off peak electricity. Have a chat with a neighbour who has electric water and space heating and find out what scheme of off peak tariff they use, the two most common be Economy 7 which is night time only and Economy 10 which is night time and some day time periods also. Study this link and then think about which is best for you:

What is Economy 10? A complete guide to Economy 10 meters and tariffs - https://www.uswitch.com/gas-electricity/guides/economy-10/#:~:text=How%20Is%20Economy%2010%20different,hours%2C%20usually%20in%20the%20afternoon.

The good thing about E7 and E10 is that they apply to all the flat's electricity consumption during the periods of lower rate which means one can with an eye on the clock or using timer functionality in the appliance run washer, dryer, dishwater or cooker and benefit from cheaper electricity. If your meter is not capable of dual rate then it will have to be swapped for one that is by your electricity supplier.

I want to see if your Landis and Gyr E470 electricity meter is capable of dual rate. Please would you follow what this short video tutorial shows and tell me what the display toggles between:

For Megan, who had a problem with her electric heating control we fitted this single timer which can control both the top and bottom elements and arrives preset with the common economy rate tariffs like E7 and E10 so all the electrician has to do is select the one you have arranged with your electricity supplier. Nice and simple to use. A rocker switch to select the bottom element Always off/timed and a button to press to increment a boost period time duration for the top element in steps of 1/2, 1 and 2 hours which can be cancelled after selection should one wish. Two lights indicate which element is on. See:

Sangamo Powersaver Dual Flexi Timer and Boost | Sangamo (PSDF2) - https://www.tlc-direct.co.uk/Products/SGPSDF2.html

 

[Nicole_]

So, the electrician came and he said everything looks fine. He took the cover out of the switches to check the cables and he said there is nothing wrong. He set the times and raised the temperature on the thermostat. Will keep an eye to see if the water gets heated etc now.

For the flashing light, he said it’s just the neon that is not working.

About the grasslin- If I have it on the constant on mode, then does it matter if the time is wrong when I switch it on?

I need to look at the tariff.

I need to dedicate an evening reading through all this information you have provided and understand things better. All these are so new to me and I’m trying to understand.