Can gas boiler heating be on during water cut off.

Ambersky

Hi All
A friend of mine just told me the water supply is being switched off in Dublin tonight from 7pm.
I was also told that I cant have my Condensing Type gas boiler running without a water supply.
Is this true?
I know it may sound like a silly question but now Im a bit worried even though I reckon there would be warnings issued already if it were so.

meercat

yeah no worries
fire away
stay warm;)

Ambersky

Thanks meercat for your quick reply.
I didnt expect to be able to get through to Bord Gas at this time but on the phone someone told me I could use the boilers heating system but if it was a combi boiler I should set it to heating rads only no water.
Now whats a combi boiler?

Joey the lips

Ambersky wrote: »

Thanks meercat for your quick reply.
I didnt expect to be able to get through to Bord Gas at this time but on the phone someone told me I could use the boilers heating system but if it was a combi boiler I should set it to heating rads only no water.
Now whats a combi boiler?

Says it perfectly....

I think i will sticky this as this is going to pop up more over the next few nights...

ntpm

Ambersky wrote: »

Hi All
A friend of mine just told me the water supply is being switched off in Dublin tonight from 7pm.
I was also told that I cant have my Condensing Type gas boiler running without a water supply.
Is this true?
I know it may sound like a silly question but now Im a bit worried even though I reckon there would be warnings issued already if it were so.

Condensing boilers are more efficient then standard boilers.
But "Condensing term" does not destinguise how they are fed or heat water and radiators.

Rule of thumb::D
If the water mains are off:

COMBI BOILER: (Combination Boiler)
1.Heats water directly from mains to hot taps.
> DO NOT USE TAPS/ HOT WATER MODE.

2.Heats water for Radiators
> OK TO USE CENTRAL HEATING MODE.

OTHER BOILERS:

OPEN VENTED SYSTEMS (Small Feed and expansion Tank in attic)
1. Heats water via a CYLINDER
> OK TO USE HOT WATER.
BUT CHECK LARGE TANK IN ATTIC HAS WATER.(If Open Vented cylinder).

2.Heats water for Radiators
> OK TO USE CENTRAL HEATING MODE
BUT CHECK SMALL TANK IN ATTIC HAS WATER.(open vented heating system)



SEALED SYSTEM BOILERS. (Red Expansion vessel in boiler/or on pipework)
1. Heats water via a CYLINDER
> OK TO USE HOT WATER.
BUT CHECK LARGE TANK IN ATTIC HAS WATER.( If Open Vented cylinder).

2.Heats water for Radiator system
> OK TO USE CENTRAL HEATING MODE
BUT CHECK PRESSURE GAUGE on boiler/ or on pipework. (normall 1-1.5 Bar min/ cold)


PRESSURISED HOT WATER CYLINDERS:
These may be mains fed
> CAN NOT BE USED TO HEAT WATER (if mains are off).

Feed via a booster pump served via a break tank/ Large storage tank.
>OK TO USE BUT CHECK TANK HAS WATER.

SOLID STOVE HEATING:
> OK TO USE
BUT CHECK SMALL TANK IN ATTIC HAS WATER. (open vented system)
Important to check this regulary if water off for a few days.

Cuairteoir

To meeting the insurance requirements in our family home, which is empty so insured as a holiday home, I have to leave the heating on enough to maintain a temp of over 10 C but also drain down the water system and turn off the water at the mains. I did that last time I visited, but left enough water in attic tank to be sure the hot water cistern was also full. Now, there is another visitor in the house who says the water is off everywhere due to the snow but he has accidentally drained the hot water cistern. This cistern can be heated by either the immersion switch or the central heating. I've told him not to turn on the immersion but if he leaves the central heating on, is there a risk of damage to the tank? If so, is the damage likely to be a leak OF the tank or a leak IN the tank? If it's in the tank, could this 'drain' the central heating system and cause a hazard with the gas boiler when it doesn't have a closed system to heat? Not sure what to advise visitor to do! They're not the 'locate the valve' type and I'm miles away. Should I tell him to just turn the heating off when he leaves? Any help appreciated! Panicing here!

Buford T Justice

The hot water tank should still be full. If the header tank is empty it won't drain the cylinder as there is no pressure to push the water out of the tank. heating should be fine.

Bruthal

ntpm wrote: »

SEALED SYSTEM BOILERS. (Red Expansion vessel in boiler/or on pipework)
1. Heats water via a CYLINDER
> OK TO USE HOT WATER.
BUT CHECK LARGE TANK IN ATTIC HAS WATER.( If Open Vented cylinder).

Id say even with attic tank empty it will be ok to run this. The hot water cylinder will not be empty, and even if it was the coil through it is just a pipe carrying the hot water into and out of the cylinder which wont get any hotter than the rad`s. Its just like another rad really.

Bruthal

Cuairteoir wrote: »

To meeting the insurance requirements in our family home, which is empty so insured as a holiday home, I have to leave the heating on enough to maintain a temp of over 10 C but also drain down the water system and turn off the water at the mains. I did that last time I visited, but left enough water in attic tank to be sure the hot water cistern was also full. Now, there is another visitor in the house who says the water is off everywhere due to the snow but he has accidentally drained the hot water cistern. This cistern can be heated by either the immersion switch or the central heating. I've told him not to turn on the immersion but if he leaves the central heating on, is there a risk of damage to the tank? If so, is the damage likely to be a leak OF the tank or a leak IN the tank? If it's in the tank, could this 'drain' the central heating system and cause a hazard with the gas boiler when it doesn't have a closed system to heat? Not sure what to advise visitor to do! They're not the 'locate the valve' type and I'm miles away. Should I tell him to just turn the heating off when he leaves? Any help appreciated! Panicing here!

It will be fine, as fingers mcgee said, only the attic tank can empty, the hot water cylinder wont, but even if it did, the central heating would still be ok to run. The cylinder cant empty though so its fine.

natsuko

i know someone was just told by bord gais not to use the gas boiler cos the pipes were frozen in the attic, is this right, or can she use it to heat the rads? Its her only heating.

Bruthal

natsuko wrote: »

i know someone was just told by bord gais not to use the gas boiler cos the pipes were frozen in the attic, is this right, or can she use it to heat the rads? Its her only heating.

Well i would think its fine to use it, especially if the boiler is inside the house so no pipes are frozen to the boiler itself. Keep an eye on the pressure gauge for the first while its going.

Cuairteoir

Thanks so much! That's put my mind at rest!!

robbie7730

robbie7730 wrote: »

Id say even with attic tank empty it will be ok to run this. The hot water cylinder will not be empty, and even if it was the coil through it is just a pipe carrying the hot water into and out of the cylinder which wont get any hotter than the rad`s. Its just like another rad really.

I was wondering about lighting the fire with attic tank empty.I thiought the cylinder tank in the press would be empty too.

Bruthal

Deleted User wrote: »

I was wondering about lighting the fire with attic tank empty.I thiought the cylinder tank in the press would be empty too.

The cylinder cant empty through the taps, so it should be ok once the pipes in the house are not frozen

WildOscar

robbie7730 wrote: »

The cylinder cant empty through the taps, so it should be ok once the pipes in the house are not frozen

can you expand on that please? do you mean the cylinder in the hot press.how does it empty? mine is empty afaik and not sure if can turn on boiler.

Bruthal

WildOscar wrote: »

can you expand on that please? do you mean the cylinder in the hot press.how does it empty? mine is empty afaik and not sure if can turn on boiler.

When you turn on a hot tap in kitchen for example, water comes out of the hot press cylinder via a pipe out of the top of cylinder, water comes into the cylinder from the attic storage tank through a pipe which goes into the bottom of the cylinder.

When the attic tank empties, no more water can go into the cylinder to allow water to go out of the top pipe, there is no longer the head of water above to give the flow out of cylinder. And once the cylinder level drops even a few mm below the top pipe out to hot taps there is no way the cylinder can now have water go to the hot taps. So the cylinder can not empty. In reality the flow stops when the pipe from attic tank has water to a level around the same as the top of the cylinder, or just above this.

When water stops from hot taps the cylinder in your hot press will still be full of water. Only the attic tank will be empty.
If you bang the side of cylinder with your hand you can tell its full of water, it sounds heavy, where as empty it will sound hollow.

WildOscar

robbie7730 wrote: »

When you turn on a hot tap in kitchen for example, water comes out of the hot press cylinder via a pipe out of the top of cylinder, water comes into the cylinder from the attic storage tank through a pipe which goes into the bottom of the cylinder.

When the attic tank empties, no more water can go into the cylinder to allow water to go out of the top pipe, there is no longer the head of water above to give the flow out of cylinder. And once the cylinder level drops even a few mm below the top pipe out to hot taps there is no way the cylinder can now have water go to the hot taps. So the cylinder can not empty. In reality the flow stops when the pipe from attic tank has water to a level around the same as the top of the cylinder, or just above this.

When water stops from hot taps the cylinder in your hot press will still be full of water. Only the attic tank will be empty.
If you bang the side of cylinder with your hand you can tell its full of water, it sounds heavy, where as empty it will sound hollow.

oh i see the thick -me-has begun to plotten:D so its ok to have boiler on.? Thanks a lot for that explanation;) am beginning to get it now

Bodhan

Hi guys, thanks for starting this thread, I have a sealed system, it's a Mynute 25HE from Vokera.

The pressure gauge on the front says zero bar (it's normally 1.5bar) there's another gauge in the hot press that says zero. The water has been off in the house for a couple of days from burst pipes in portlaoise.

The boiler seems to want to start the whole time, theres a click, hum and then it cuts out. I'm not trying to start the heaters, I have it turned off. Is it making this noise from the low pressure or something?

Joey the lips

Bodhan wrote: »

Hi guys, thanks for starting this thread, I have a sealed system, it's a Mynute 25HE from Vokera.

The pressure gauge on the front says zero bar (it's normally 1.5bar) there's another gauge in the hot press that says zero. The water has been off in the house for a couple of days from burst pipes in portlaoise.

The boiler seems to want to start the whole time, theres a click, hum and then it cuts out. I'm not trying to start the heaters, I have it turned off. Is it making this noise from the low pressure or something?

Is it zero when its off.

Does the pressure gague in the hot press have a red needle set at 1,5 bar.

I am guessing you have an auto filling valve(Black valve) which is slightly open to let in pressure. This has no pressure so the system has wound down.

Would this sound right.

Bodhan

Joey the lips wrote: »

Is it zero when its off.

Does the pressure gague in the hot press have a red needle set at 1,5 bar.

I am guessing you have an auto filling valve(Black valve) which is slightly open to let in pressure. This has no pressure so the system has wound down.

Would this sound right.

Sorry I'm not very heating minded...
Yes the needles are zero when it's off.
There's no needle set to 1.5bar, there's only a gauge thats at zero and yes this has a label that says auto filling valve. On one side of it theres a knob with no markings.

The boiler is still making noise no matter what I do. It's been at it so long it's tripped the fuse which turned out the lights!

How do I refill the water in the boiler, or turn off the boiler altogether?

Joey the lips

Bodhan wrote: »

Sorry I'm not very heating minded...
Yes the needles are zero when it's off.
There's no needle set to 1.5bar, there's only a gauge thats at zero and yes this has a label that says auto filling valve. On one side of it theres a knob with no markings.

The boiler is still making noise no matter what I do. It's been at it so long it's tripped the fuse which turned out the lights!

How do I refill the water in the boiler, or turn off the boiler altogether?

You cannot fill the system without mains pressure or a long garden hose from your neighbours mains.

You will need to have the system restored by a plumber once the mains comes back.

I would also suggest you have the plumber remove the auto filling valve and fit a combi filling loop which should be disconnected once the system is filled.

The system you have in my opinion should be outlawed. For 2 reasons.

1. If there is a leak in the system it can be used to mask it by constantly keeping the pressure high. However this has the effect of introducing new water all the time therefor leading on ongoing corrosion of the heating system

2. In times of perlonged pressure drop your system can cut out. This pressure drop occurs at times of extrame cold usually and this is what happened to you.(The pressure drop is from burst mains)

Sandraf

Another blond one here - I understand the gas boiler heating is ok to be on when the water is turned off. What I don't understand is why my vent on the outside wall has begun to "rattle" and make noise when the heating goes into its second hour of being on. This has only started since the water went off. Any ideas ?

Joey the lips

Sandraf wrote: »

Another blond one here - I understand the gas boiler heating is ok to be on when the water is turned off. What I don't understand is why my vent on the outside wall has begun to "rattle" and make noise when the heating goes into its second hour of being on. This has only started since the water went off. Any ideas ?

What vent. Can you take a picture.

Sandraf

Thanks for the reply joey. Its the vent from the boiler to the outside world that spews out fumes! Tis fixed now. Apparently me fan was gone. God bless WD40 or whatever he used! Cheers

fibber

I'm in a rented house so I don't really know the system. My boiler just won't start when the mains goes off- It's been like that for the last few days- off in the evening and it's maybe 9-10am before the mains returns- and so then the boiler- (pain in the neck with a week old baby in the house- My question is though it's gone off again this evening and that is just with reduced pressure from the mains taps - We haven't really used the hot taps at all. can it be directly connected to the mains somehow - Is there some trouble shooting we can do to get it functioning? Tonight is the first night it has given a red flashing light for no flame.. Should I switch it off completely every night?

Bruthal

fibber wrote: »

I'm in a rented house so I don't really know the system. My boiler just won't start when the mains goes off- It's been like that for the last few days- off in the evening and it's maybe 9-10am before the mains returns- and so then the boiler- (pain in the neck with a week old baby in the house- My question is though it's gone off again this evening and that is just with reduced pressure from the mains taps - We haven't really used the hot taps at all. can it be directly connected to the mains somehow - Is there some trouble shooting we can do to get it functioning? Tonight is the first night it has given a red flashing light for no flame.. Should I switch it off completely every night?

Possibly its a sealed system but the mains filler is still connected to it and open, thats a possibility. So with mains pressure low the boiler is not running. If this is the case then find the mains filler and close its valve, and see if that helps.

fibber

Thanks for coming back Robbie- I know this is probably futile given you can't see the system - but what would that look like ? and where might it be situated - Attic or around the boiler?

Much appreciated.

Bruthal

fibber wrote: »

Thanks for coming back Robbie- I know this is probably futile given you can't see the system - but what would that look like ? and where might it be situated - Attic or around the boiler?

Much appreciated.

Well my above post might not be the problem, its assuming its a sealed system. But if it is, the filler valve may be hard to find. Often they are in the hot press feeding into the heating coil which are the 2 pipes into the side of the cylinder, one near bottom and other neared the top(filler may be into one of these), usually with an automatic air vent near it. Sometimes they have a silver flexible hose which is supposed to be disconnected once the system is filled. Other than that it would be hard to find it unless you know what to look for.

fibber

Thanks for that Robbie- Couldn't find it :P just going to stick with the massively expensive gas fire and hope that they manage to fill the reservoir soon!

danjo

robbie7730 wrote: »

Id say even with attic tank empty it will be ok to run this. The hot water cylinder will not be empty, and even if it was the coil through it is just a pipe carrying the hot water into and out of the cylinder which wont get any hotter than the rad`s. Its just like another rad really.

If the heating is set to maintain a fixed room temperature and there is no draw from the hot water cylinder then the water in the cylinder will be constantly heating. Assuming there is no cylinder stat then the water in the cylinder could boil over into the attic tank. So what happens if the attic tank is empty?

Bruthal

danjo wrote: »

If the heating is set to maintain a fixed room temperature and there is no draw from the hot water cylinder then the water in the cylinder will be constantly heating. Assuming there is no cylinder stat then the water in the cylinder could boil over into the attic tank. So what happens if the attic tank is empty?

If the central heating boiler is set to heat the water/rads to 80 degrees C for example, and the hot water cylinder has no stat/motorised valve then the water in the cylinder can only heat to the same temp the boiler can reach, so the cylinder water cant go to a higher temp than the boiler is set to. It wont just keep getting hotter once it reaches 80 degrees in this example. The idea of a cylinder stat is that the cylinder would not need to be as hot as the rads would usually.