direct 210 l unvented water heater cylinder that has been drained down

[peterpeter]

Hi
l just bought an empty flat, where the water was turned off and the
electric too
ive turned the electric on but when l turned the water on the direct
unvented water heater ( a tribune range he ) fills but the then the
water comes out of the overflow ( tundish ) until l turn the water off
at the main
is there anything that l should be doing once the water has been turned
off and the system drained please.
all the taps around the flat work ok when the water is turned on
l havn't tried to switch the 2 immersions on at all
l need help please




--
peterpeter

[John Rumm]

Sounds like one of two possibilities[1] - either the pressure reducing
valve is not working correctly and you have very high mains pressure
water, or an overpressure release valve is opening when it should not
(or is stuck open due to debris lodged in it).

Typically there is a PRV on the mains inlet to limit the pressure to
around 3 - 3.5 bar. There are two over pressure relief valves. One is a
combined over temperature and over pressure valve (usually on the side
of the cylinder toward the top), and the other is a overpressure /
expansion relief valve - typically built into the Pressure reduction
valve. Both valves should feed via pipes to the tundish. Both relief
vales usually have a red knob on the top, which should turn a short
distance to open the valve manually and then spring back to the closed
position when you let go. I would try operating both a couple of times
manually to make sure there are doing what they should.


[1] The third possibility would only really apply as the cylinder heats
up - and that would be if the expansion vessel has lost its charge of
air meaning there is no expansion space and that forces the pressure to
rise to high.

--
Cheers,

John.

/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/

[peterpeter]

John Rumm;2993658 Wrote:
> On 09/01/2013 22:52, peterpeter wrote:-

> Hi
> l just bought an empty flat, where the water was turned off and the
> electric too
> ive turned the electric on but when l turned the water on the direct
> unvented water heater ( a tribune range he ) fills but the then the
> water comes out of the overflow ( tundish ) until l turn the water off
> at the main
> is there anything that l should be doing once the water has been
> turned
> off and the system drained please.
> all the taps around the flat work ok when the water is turned on
> l havn't tried to switch the 2 immersions on at all

> l need help please-

>
> Sounds like one of two possibilities[1] - either the pressure reducing
> valve is not working correctly and you have very high mains pressure
> water, or an overpressure release valve is opening when it should not
> (or is stuck open due to debris lodged in it).
>
> Typically there is a PRV on the mains inlet to limit the pressure to
> around 3 - 3.5 bar. There are two over pressure relief valves. One is a
>
> combined over temperature and over pressure valve (usually on the side
> of the cylinder toward the top), and the other is a overpressure /
> expansion relief valve - typically built into the Pressure reduction
> valve. Both valves should feed via pipes to the tundish. Both relief
> vales usually have a red knob on the top, which should turn a short
> distance to open the valve manually and then spring back to the closed
> position when you let go. I would try operating both a couple of times
> manually to make sure there are doing what they should.
>
>
> [1] The third possibility would only really apply as the cylinder heats
>
> up - and that would be if the expansion vessel has lost its charge of
> air meaning there is no expansion space and that forces the pressure to
>
> rise to high.
>
> --
> Cheers,
>
> John.
>
> /=================================================================\

> | Internode Ltd - 'Internode Limited - Computer Consultancy
> and Software Development' (http://www.internode.co.uk) |

> |-----------------------------------------------------------------|
> | John Rumm - john(at)internode(dot)co(dot)uk |

> \=================================================================/r/ Thank you John for your help/ ive just realised that when l turned
the water on /after the system being drained down by the foreclosure
company, the water tank isn't filling ,As ,as soon as the water flows
out of the tundish and l turn the water supply off then there is no
water at the taps ( forsetts ) or at the shower so the cylinder isn't
filling/ how do l fill the cylinder once the water supply is turned on ?
l think l have to open a valve to get the tank to fill but im not sure
which valve to open/ the 2 valves which you mention./ l have tried and
all that seems to happen is a surge of water goes through the tundish
when l turn each valve/ l don't think there is anything wrong with the
system but l don't know how to refill the water tank / any help would be
gratefully accepeted/ l should re adjust my question and do a new one
and cancel the original one regards from the UK/ best wishes Peter




--
peterpeter

[John Rumm]

On 10/01/2013 20:13, peterpeter wrote:

> Thank you John for your help/ ive just realised that when l turned
> the water on /after the system being drained down by the foreclosure
> company, the water tank isn't filling ,As ,as soon as the water flows
> out of the tundish and l turn the water supply off then there is no
> water at the taps ( forsetts ) or at the shower so the cylinder isn't

Reading between the lines here, I doubt the cylinder was actually
drained at all... (its not in fact that easy to drain one since the hot
water only comes out of the top of it, when mains pressure cold water
flows into the bottom to make this possible. Draining in the true sense
usually requires attaching a hose to a drain valve at the bottom of the
cylinder)

If when you turned the supply onto the cylinder, the hot taps worked
then the cylinder *must* already be full.

If you turn the mains supply on, and get nothing but air out of the hot
taps, then the cylinder really is empty.

> filling/ how do l fill the cylinder once the water supply is turned on ?
> l think l have to open a valve to get the tank to fill but im not sure
> which valve to open/ the 2 valves which you mention./ l have tried and

The correct sequence is to open a hot tap somewhere, and then turn on
the supply to the cylinder. This will allow the air in the cylinder to
be displaced and pushed out of the tap. The cylinder will fill, pushing
out al the air until there is none left. Once water starts flowing from
the tap the cylinder is full, and you can turn the tap off.

Once you turn off the tap, water will also stop flowing into the
cylinder. At no point should any of the safety valves discharge into the
tundish. (a short burst of discharge that then stops shortly afterwards
might indicate lack of expansion space in the pressure vessel)

If with the supply on, and all the hot water taps closed there is a
continuous flow into the tundish, then something is wrong.

> all that seems to happen is a surge of water goes through the tundish
> when l turn each valve/ l don't think there is anything wrong with the

If you manually operate either valve when the mains supply is on, then
this is exactly what should happen. However once you let go of the test
knob on the valve - they should spring shut and no further water should
flow to the tundish (it may dribble for a bit - but there should be no
ongoing flow).

> system but l don't know how to refill the water tank / any help would be
> gratefully accepeted/ l should re adjust my question and do a new one
> and cancel the original one regards from the UK/ best wishes Peter

You can't cancel your message out here on usenet:

http://wiki.diyfaq.org.uk/index.php?title=Newsgroup_access_tips

and most of us are in the uk since this is the uk.d-i-y newsgroup ;-)


--
Cheers,

John.

/=================================================================\
| Internode Ltd - http://www.internode.co.uk |