Anyone know a bit about boilers?

[abillybob]

Hey Guys

 

So since we've moved in for the majority of the time we don't have any problems. We have the hot water on in the morning before we get up for work for half an hour and then it turns on again at around 4:30 before we get back from work for another half an hour. Most days we've had hot water start to finish every day which is what we want although some days it's not hot at all!

 

We've found that when our hot water turns on in the morning our boiler (This one to be exact A Rated Unvented - Tempest Plus) will make a vibrating/humming noise sometimes. It's not overly loud but enough so you can hear it! When it does this noise we tend not to have any hot water it will come out cold after it's been on for the 30 minutes. It's an electric system not gas and we seem to have two boilers one is the tempest thingy above with a large tank which I presume does the water and the other is a smaller vertical thing (this to be exact https://www.heatandplumb.com/images/products/heatrae_sadia/main/main_product_134100.jpg) We also have an expansion vessel which shows the pressure of the water I think which at the moment is at 0.5bar but there's a sticker on the unit itself with a red pointer that I think is trying to tell me it should be there although I haven't got a clue on how to raise the water pressure... Here's the pictures of our expansion vessel https://photos.google.com/share/AF1QipNM_344ZRpfJ6YgGgFM8sBUiXg3h_Zl8QznY470RnzeAxKhR3O_Suluq5xhGo8JKg?key=MEhfeE5FakFtSHNsR3VwNTRjN2dSMGdrUDFvdzFn

 

Sorry I know you guys aren't plumbers but I though maybe one of you has an idea and can help or tell me what's right or wrong?

 

Thanks

 

PS we've never had a problem with central heating only the water.

[Gurtlush]

So first off the pressure is to low, to re-pressurise you normally have a tap (or taps) to turn to add pressure from the mains. Google how to re-pressurise central heating system and you'll get loads of videos. It's very easy and simple and should only takes a few seconds to do.

That may fix the problem but hummimg or vibrating could be air in the system so you might have to bleed a radiator or two (again quite easy) but since it's a pressurised system you'll have to replace the air with water by doing the above.

As always if it gets to complicated it should only take a plumber 30 mins to sort provided it's not something else.

[abillybob]

So first off the pressure is to low, to re-pressurise you normally have a tap (or taps) to turn to add pressure from the mains. Google how to re-pressurise central heating system and you'll get loads of videos. It's very easy and simple and should only takes a few seconds to do.

That may fix the problem but hummimg or vibrating could be air in the system so you might have to bleed a radiator or two (again quite easy) but since it's a pressurised system you'll have to replace the air with water by doing the above.

As always if it gets to complicated it should only take a plumber 30 mins to sort provided it's not something else.

 

Thanks for your help! I've re pressurized the tank so that the needle is exactly where the red needle on the sticker is. Although after the red needle on the sticker it shows a green band up to about 3 bar should it be at the top of that or where the needle is?

 

I will go round and bleed all the radiators although all of the radiators are hot top to bottom so do you think there is a need or would you expect that's why we are having noise because somewhere there is air?

[elsiegee40]

The pressure in the system will fluctuate as the system runs/shuts off . As it gets hot the pressure will rise and it will fall as it cools down again.

 

If it's running OK then pressure is unlikely to be a problem. If you over-pressurise you will have water pouring out of an overflow outside somewhere.

 

Noise is more likely to be air in the system somewhere. Getting rid of it can be quite tricky.

Edited January 21, 2017 by elsiegee40

[jmak]

If the noise is only when the boiler is making hot water, you won't sort anything by bleeding the radiators. Air in the system is a good call, but the circuit of water in your radiators does not connect to what comes out of the taps anywhere.

 

Last time I was trying to sort air in our system, I connected the cold main in to the hot supply for the washing machine to force water at pressure back through the system - not necessarily the text book way of doing it, but plenty of YouTube vids! The other place you might have a mains cold feed next to a hit tap is the kitchen sink.

[CAM]

My boiler was at 0.9 bar over Christmas and it tripped a safety mechanism that stopped it from operating. I had to fill it up to over 1 bar but I went to 2 bar to give a bit of leeway. 3 bar is the upper red zone. You might want to get it serviced during the spring just in-case!

[Willott]

So your first link is an unvented cylinder - this is not a boiler, but may well have an immersion heater in to heat the water - but it may also be fed from boiler as well. The longer thin (from a brief google) appears to be a flow boiler and this will be what's heating your water. It's difficult to tell without seeing your piping arrangement as to what feeds what, or exactly where the issue lies, but as others have said, it sounds like it may be air or pressure related. Have you noticed in improvement since you've got the pressure up to 1.5bar?

[abillybob]

So your first link is an unvented cylinder - this is not a boiler, but may well have an immersion heater in to heat the water - but it may also be fed from boiler as well. The longer thin (from a brief google) appears to be a flow boiler and this will be what's heating your water. It's difficult to tell without seeing your piping arrangement as to what feeds what, or exactly where the issue lies, but as others have said, it sounds like it may be air or pressure related. Have you noticed in improvement since you've got the pressure up to 1.5bar?

 

Unfortunately not. Woke up this morning to cold water again It was fine yesterday very hot but this morning was colder than a cold thing!! Don't really understand how it can be fine one day and then cold the next day especially when none of the settings have been changed!

[Willott]

Pressure still at 1.5bar? Couple of other possibilities - http://www.directheatingsupplies.co.uk/pdfs/Telford%20Tempest%20+%20Tornado%20Guide.pdf appears to be the guide and things to check - if you can also post a pick of the tank, it may give some clues as to direct/indirect and other config.

[elsiegee40]

Do you have a hot water tank?

 

If the stored water is going cold overnight then it needs insulating properly.

 

If the water and heating come on at the same time, you may find that it's heating the house as a priority over heating the water. You may need the water system to come on half an hour or so before the heating.

[noelmm]

It may be that the water heating coming on for only 30 minutes is not long enough to heat the water on colder days. Don't forget the ambient temperature of the water coming in will be colder so therefore take longer to heat up.

 

When you have no hot water have you tried turning the boiler onto a manual cycle for an hour (maybe 2) and see if this has any improvement?

Edited January 23, 2017 by noelmm

[abillybob]

Pressure still at 1.5bar? Couple of other possibilities - http://www.directheatingsupplies.co.uk/pdfs/Telford%20Tempest%20+%20Tornado%20Guide.pdf appears to be the guide and things to check - if you can also post a pick of the tank, it may give some clues as to direct/indirect and other config.

Not sure I haven't checked. I'll have a look when I get home and I'll post some pictures of the setup!

 

Do you have a hot water tank?

 

If the stored water is going cold overnight then it needs insulating properly.

 

If the water and heating come on at the same time, you may find that it's heating the house as a priority over heating the water. You may need the water system to come on half an hour or so before the heating.

 

Yes I think we do have a hot water tank which is the unvented cylinder thingy, it seems to be quite well insulated as far as I'm aware they're meant to be very good.

 

Good idea I may try this and see if it improves but surely then it'd be the case we wouldn't have hot water every morning rather than some morning and not others.

 

 

It may be that the water heating coming on for only 30 minutes is not long enough to heat the water on colder days. Don't forget the ambient temperature of the water coming in will be colder so therefore take longer to heat up.

 

When you have no hot water have you tried turning the boiler onto a manual cycle for an hour (maybe 2) and see if this has any improvement?

I did think that maybe it's just colder days and normally if I put it on for another hour it's all good so maybe we should put it on for longer but it's annoying as an hour a day normally does us two and it's such a waste of electric when we're heating the water for longer when we don't need to.

[sippo]

Just throwing it out there - but why not get a plumber in to check it out professionally?

[abillybob]

Just throwing it out there - but why not get a plumber in to check it out professionally?

OMG.

 

 

Cheers for your helpful advice as always Sippo.

[Willott]

Just throwing it out there - but why not get a plumber in to check it out professionally?

 

Because a plumber is at least a £40 callout charge - whereas some of us may have had experience with similar setups, or may, perhaps, have plumbers in the family/friends/circle of trust who may be able to suggest a couple of things to try before getting a plumber in - which ideally, any decent plumber would want you to do - sure, they get £40, but they have to trek across to your house to turn 1 valve, make everything happy again, and then trek back.

[sippo]

I know a good plumber and he doesn't charge a call out fee. If the work is worth it, most good ones won't charge it. It sounds like it could be planned anyhow.

 

It's better to pay a callout fee anyway rather than a later big cost later on.

 

It's all well and good asking the web for advice, but you still need the knowhow and knowledge, to put that theory into practice.

[pcstru]

We've found that when our hot water turns on in the morning our boiler (This one to be exact A Rated Unvented - Tempest Plus) will make a vibrating/humming noise sometimes.

That is a hot water tank and the one pictured has an immersion heater fitted (the yellow thing sticking out the bottom half of the tank). These do sometimes make a noise similar to a kettle when heating the water. They can take quite a while to heat the water if starting from a full tank of cold water.

 

It's not overly loud but enough so you can hear it! When it does this noise we tend not to have any hot water it will come out cold after it's been on for the 30 minutes. It's an electric system not gas and we seem to have two boilers one is the tempest thingy above with a large tank which I presume does the water and the other is a smaller vertical thing (this to be exact https://www.heatandplumb.com/images/products/heatrae_sadia/main/main_product_134100.jpg) We also have an expansion vessel which shows the pressure of the water I think which at the moment is at 0.5bar but there's a sticker on the unit itself with a red pointer that I think is trying to tell me it should be there although I haven't got a clue on how to raise the water pressure... Here's the pictures of our expansion vessel https://photos.google.com/share/AF1QipNM_344ZRpfJ6YgGgFM8sBUiXg3h_Zl8QznY470RnzeAxKhR3O_Suluq5xhGo8JKg?key=MEhfeE5FakFtSHNsR3VwNTRjN2dSMGdrUDFvdzFn

 

The expansion vessel is to do with the heating system (I presume you have radiators) and should have nothing to do with the hot water unless the set-up is very wierd (a hot water loop from the heating system into the hot water tank). The pressure on the expansion vessel should be around 1 bar when the system is cold (and has been bled). It will go up a little when the system is hot.

 

Sometimes people do have wet loops into the hot water tank - I have one because my wood burner has a back boiler, but I'd not expect anyone to feed that loop from the central heating (i.e. the heating system has nothing to do with the problem of hot water).

 

Presumably the controls are different for the hot water and the heating (you can have them on at different times)?

[clareq]

We insure our boiler with British Gas (I'm sure other providers are available) A service every year and any repairs needed for about a tenner a month. You can even call them in to fix a problem for a fixed price then take up the insurance.

[mikkydoos]

but they have to trek across to your house to turn 1 valve, make everything happy again, and then trek back.

 

A bit like us!

[mikkydoos]

Put your water heating on for about 3 hours. Don't use the timer, put it ON... timer could be faulty.

Put the temperature to FULL. Thermostat could be faulty.

 

If the water isn't warm or hot you have an issue with the thermostat or the element in the tank. Nothing else it can be.

 

The red cylinder in your loft is the water tank/pump for your central heating by the look of it. Get the pressure in the middle of the big green triangle or that will be really inefficient too.

[Homer]

To me it looks as if the tall unit is heating the water going to the radiators judging as it has flow return. The Tempest will be your calorifer (water heater) and will heat the water contained within and then keep it hot as well - within reason.

 

I don't know what power the immersion is specified on there but for arguements sake it's a 3kw model, if you only run it for 1hr a day you're only putting 3kw into the tank and given how cold the water is probably taking more than 3kw of heat out of it.

 

As a starter I would suggest running it for an hour in the morning (depending on your use) and a couple of hours in the evening. It will cost more, but it will ensure the water stays hot. However if it used to be hot and now is not, it may be worth calling somebody in to take a look. The water coming in to your house at the moment will be very cold so it will have to work harder. Try running it longer at first, see if that works.

 

Also, see if there is a small pump attached to the water heater. There will be one for the central heating, but this cylinder may have a destratification pump which should circulate the water in the cylinder to heat it evenly, if this isn't working it may be stopping it heating up properly (this would explain the noise)

 

Those are my best guesses! Good luck

 

Also - with regards to the pressure, look for a filling loop for the radiator circuit. It may be worth taking some pictures of the cupboard all of this is in so we can pick it apart a bit better. Both systems, unless the radiator circuit is vented, should have a expansion vessel.

Edited January 23, 2017 by Homer

[abillybob]

Thanks for all the help guys and all the responses it's most appreciated. Here's a picture of our setup, it's not the best picture I'll get a better one tonight if these aren't good enough!!

[Willott]

It looks like there's a further white tank to the left - possibly another expansion vessel - would be useful seeing that as well when you get a chance for a decent picture.

[mikkydoos]

It looks like there's a further white tank to the left - possibly another expansion vessel - would be useful seeing that as well when you get a chance for a decent picture.

 

That looks like expansion for the water heater looking at the pipe route.

 

 

Its worth mentioning that expansion vessels have an 'inner tube' inside them that requires being inflated. That can play havoc with combi boiler water pressures.

I wonder if that would affect your water heater? Hhhhmmm.

Edited January 23, 2017 by mikkydoos

[pcstru]

Its worth mentioning that expansion vessels have an 'inner tube' inside them that requires being inflated.

The vessel is usually in two halves separated by a rubber diaphragm. Red expansion vessels are for hot sealed systems, white and blue are for open systems often with potable water.

 

In OP's system we can see from the picture that the hot water is being done by an immersion heater in the big tank and immediately above the immersion looks like some kind of thermostat (?). So if there is a problem with hot water, it is going to be reactively simple (immersion, thermostat or the controller which switches it on).