smelly hot water and very limited hot water each time. how can I fix these?

[MrsHou]

hello everyone. We use Heatrae sadia Megaflo high efficiency water cylinder/boiler. We have no gas comes in the building. Our hot water has funny sour smell like yoghurt. Every time I turn on hot water the smell will comes up. After hot water running for 1 to 2 minutes, the smell will get less strong. but it's still annoying and we want to fix that. Does anyone know what's wrong with my hot water?

beside the smell, I also have very limited use of hot water for shower.what I will prefer is unlimited use of hot water. So, we can shower as long as we want. and everyone at the family can shower at the same night. I usually end up use all the hot water. So my husband has to wait hours to have enough hot water again to shower.

Does anyone know how can we get rid of the hot water smell and can have unlimited use of hot water for shower? we had talk to a plumber about it. he said electric combi boiler can do it, but it is going to charge 5000 pounds beside the pipe work which is going to be another thousand pounds. because electric combi boiler is unusual at UK. Is that true? is it that expensive to install an electric combi boiler and it is not popular at UK?

the plumber recommend to instead just replace our old cylinder to get a new one that works the same. but then I still got limited use of hot water. Do you think if I can have better option that this?

Combi boilers are best. I think you can get one for less than that - shop around.

What kind of boiler do you have at the moment? Do you need to turn you water on to heat it up or do you need to turn your thermosat up to get it get it hotter?

The smell is unusual. An unvented cylinder should be fed direct from the incoming water main supply so the water should be perfectly clean.

Is the water pressure so strong that when you put your thumb over the hot tap, you can't stop the flow?

Are there any other water tanks in the house or flat, perhaps on the loft or on top of this cylinder? Post some photos of it please.

As for the time to heat, it presumably has an electric immersion heater. That will take about one minute to heat one litre of water from cold to hot. A bath might use about 100 litres of water so you will need to heat it for about an hour and a half beforehand. More if you are using up the hot water in sinks.

Do you use storage heaters with an off-peak electricity supply?

Do you leave the immersion heater turned on continuously, or is it on a timer, or do you turn it on an off by hand?

What is the size of this cylinder?

I note that you have no gas supply so you can't have a gas boiler.

I wouldn't recommend an electric combi. It will be nowhere near as powerful as a gas combi.

The water pressure looks high enough that we can't stop it. Not sure how to do it, but it sprayed everywhere when we tried.

There's only one 145L cylinder, pictures included with this post. The top heater element is active whenever the top switch is turned on, and the bottom only during off-peak. We leave both switches on all the time.

The water in this area is pretty hard, and our best guess so far is that there's limescale buildup inside the cylinder. Would that explain the smell? The boiler instructions says to get it inspected/maintained yearly, but I'm not sure if that's been done. The apartment is 10 years old, and we recently bought it.

The top element doesn't heat the whole tank, perhaps the issue is that the bottom one doesn't actually work. The top will cost more to run also.
Check that the light on the lower switch comes on when it's night time. If not make sure the circuit breaker or fuse in the cupboard is on.
The bad smell could be caused by the stagnant water that never gets heated. It might be an idea to get it all serviced as you are supposed to check it all every year for safety reasons

the light on the lower switch does comes on at night. I feel bad to get water from a water tank because I got limited hot water and I may have smelly water again in future. I thought an electric combi boiler can solve this problem. but Piglet John said it is not powerful enough. Is that means my water will never be hot enough? or it will be hot sometime and not hot enough sometime? or what is the problem with electric combi boiler?

A gas combi boiler typically runs with about 30kW of power.

That would require an electricity supply of about 130Amps

The electricity supply to your house might be fused at 60A, 80A, or sometimes 100A.

So your entire electricity supply would be insufficient to give the same power, and the cables too small.

If the lower element in your cylinder is working, it would provide almost 145 litres of hot water. Which is adequate for about 3 showers. But if you take very long showers, or if you have a drencher/waterfall shower head that uses vast amounts of water, you might use it all up before your DH gets a shower.

Turn off the switch for the upper element, and see if the cylinder heats up. Perhaps your lower element is not working. This is quite an easy repair.

I turned off the upper switch last night to test. the down switch button is supposed to be on from 1am to 9am. but it is not on before I sleep at 2am. and when I wake up at 7:30am it is on. and it is off at 9am. So, it is on, but not on for 8 hours as it supposed to be. should I contact the person who manage the building to fix it or I just find a plumber ?

it didn't warm up much water. the hot water run for 30 seconds then it's gone. So, that means the lower element is not working properly and I should find a local plumber to change it? is that something I can do easily by myself?

you can check the tariff on your electricity bill, but it is probably 7-hours off-peak. That is more than enough time to fully heat the entire cylinder.

It does appear that your lower element is not working correctly/at all.

There is a chance that it just needs the thermostat changed (very easy, no need to drain the water) or maybe it needs a whole new element (takes longer, required draining the cylinder)

As you have an unvented (pressurised) cylinder, it has to be serviced by a person qualified to work on it, who understands the safety devices. This is called a "G3" certificate. Heating engineers who are Gas-Safe registered sometimes have it, general plumbers usually not. Try to use someone by personal recommendation, but state that it is a Megaflo which is not heating overnight, ask if they have a G3 ticket. You can verify this, if it's a gas-safe person, by looking at their ID badge or on the online Gas-safe register. There will be a tick against "+ Unvented Hot Water storage Cylinders"

If you check the readings on your electricity meter, you will probably find that the off-peak usage over the last few months has been very low, possibly nil. If it has been using 5kWh or more a night, that suggests that it has been trying to heat the cylinder but there is a leak and the hot water is escaping.

John, I took a picture of the electric meter at 1am and then take another picture of the electric meter at 10:30am. the only things are running between 1 to 10:30am are my humidifier and fridge. and the number only increase less than 1.

so, that means the down element is not working at all? and I need to change the down element? will it take care of the smelly water problem as well? what will be a reasonable price range? I may need to meet with more than 1 engineer to find a reasonable price.

If it is just the thermostat, it will be cheaper and quicker than changing the whole element, because it does not have to be drained. Maybe an hour instead of half a day. A personal recommendation is a good way to find a local heating person, but you must check their qualification before making an appointment.

Don't look on a website where the traders pay to be listed and can prevent unfavourable reviews being published. For example advertising websites that give the impression the traders have been checked.

An established local engineer who is any good will get enough recommendations from satisfied customers that she doesn't need to pay for listings.

Look for a local address and local landline number.

Thank you John for all the suggestions you gave these days. I appreciate it :)