Plumbing advice

calvincamel

A family friend ( "aunt") wants to move back to a home where the water has been off for a good year or more. I had to have a look around to assess & it all seems pretty sound. An extension was built & the house was rewired & central heating put in mid 90s, so all pipework should presumably be decent, copper. She won't have the local plumber (don't ask) and just wants to turn the water straight on. I've advised caution.

Advice/ plan needed please.

After a bit of research: I'd partially open all taps or at least the top one, turn the water on slowly at the stop !!!!!!, as the air clears through the system, checking for leaks/problems. After 5 mins or when the air is out, open the taps a bit more, until they're fully open & flow is at full pressure. Then let it run for 5, 10 minutes or until it's clear & cold. I'm wary of aerosolised water drops, due to legionnaires (I work in health) & so will clean/ descale taps, shower head. I've told her that to be safe (she's old), she should boil all drinking water for a week, just so any residue in the system is gone.

Am I being too paranoid, have I missed anything? Any suggestions welcome.

fenwick458

well I think you've pretty much covered it, the boiling water for a week sounds overkill to me but you may know better!
If it was my property I'd simply have someone open the water stop tap whilst I quickly checked/listened in the loft, bathroom and kitchen for any leaks. and I there were some, just shout down to turn the water off.
what sort of boiler is it? the absolute worst thing to do for an old boiler is leave it dormant for a year 

jbainbridge

Boil the water .. why? Run the taps, flush the toilets .. it'll be fine.

Section62

calvincamel said:

Am I being too paranoid, have I missed anything? Any suggestions welcome.

The two areas of concern for me health-wise would be the cold water storage tank in the loft, and the hot water cylinder - if the house has these.  Both will contain water which wouldn't have drained out fully just by turning taps on, and it will take time (and lots of water) to fully flush it out now because fresh water entering the system will just dilute (rather than fully replace) what is currently there.

If it was me I would make sure all water in both storages was removed before recommissioning the system - however doing this carries a risk of aerosolisation so there's a balance to be struck between the risks.  Heating the hot water cylinder to above 60 degrees should kill Legionella bacteria present, so that could be an alternative approach.


The other thing I'd take into account is if there is a cold water storage tank once this has started to refill it could continue to supply water to any defective pipework/fittings for a while, even after the main stop tap has been turned off - unless there are accessible and functional valves to isolate the tank supply to these pipes.  These valves (if fitted) often seize up and don't work when needed - so I would locate and test them before turning the mains supply back on.

If there are no such valves - or they don't work - that could be a good reason to call in a plumber to install (new) ones, and while they are to give the system a check.


If there is no bulk water storage then recommissioning is much easier - but don't forget storage in toilet cisterns, and the effectiveness of toilet flushing systems at aerosolisation.

Bendy_House

Calvincamel, do you know what sort of DHW system she has? Is it a 'combi' boiler or a stored water system? If combi, then the issue is much simpler.

The only tweak I'd make to your own plan, is that I would not first open any tap before slowly opening the stopcock. I'd want to know if any water was flowing with the taps all closed. Any flowing water would either be down to refilling tanks - CWS in the loft, toilets, etc - or a leak. 

Once I was certain there was no sign of flowing water, then I'd slowly crack open each tap at a time and allow it to purge any air and the stale water. Obviously a 'coughing' tap will run the risk of aerosols, so a mask and standing well back would be advised at the very least. 

As already mentioned, the main sources of potential hazard are the water storage tanks, hot and cold. Your aunt is moving 'back' to this home, so did she have the system drained when she left (which would have been the wise thing to have done if she'd know the house would be left for this length of time)?  

How much investigation is she capable of doing - can she check the CWS in the loft, for example? Or do you know if it's a combi boiler - much easier to deal with?

Eldi_Dos

Its sensible to be concerned about this.As offices start to open up I would hope facility managers are taking steps to purge and check water systems.

calvincamel

fenwick458 said:

well I think you've pretty much covered it, the boiling water for a week sounds overkill to me but you may know better!
If it was my property I'd simply have someone open the water stop tap whilst I quickly checked/listened in the loft, bathroom and kitchen for any leaks. and I there were some, just shout down to turn the water off.
what sort of boiler is it? the absolute worst thing to do for an old boiler is leave it dormant for a year 

Thanks for responding. I worked in community health & am just over wary of an octagenarian getting ill, especially as legionnaires is so nasty & thrives in stagnant water or even scale (& it's a really hard water area). I know it's probably being over cautious, she probably won't drink tapwater anyway (just tea) & has no teeth to brush so I reckon it's a moot point anyway. I was going to do the running up and down stairs, listening to check that the pipes fill properly & don't leak. A quick check in the loft/airing cupboard would be a safe idea too, I suppose.

Really good point about the boiler, hadn't even thought of that. It's an old back boiler so would probably need looking at (flushing/cleaning?) but a gas service is one of the things I've insisted she do before using the heating/fire, so hopefully it'd be repairable. She mostly uses a couple of electric rads at the moment, so should be fine for now.

Thanks again.

calvincamel

jbainbridge said:

Boil the water .. why? Run the taps, flush the toilets .. it'll be fine.

Thanks for responding. Just playing it safe, she's an old family friend.

calvincamel

Section62 said:

calvincamel said:

Am I being too paranoid, have I missed anything? Any suggestions welcome.

The two areas of concern for me health-wise would be the cold water storage tank in the loft, and the hot water cylinder - if the house has these.  Both will contain water which wouldn't have drained out fully just by turning taps on, and it will take time (and lots of water) to fully flush it out now because fresh water entering the system will just dilute (rather than fully replace) what is currently there.

If it was me I would make sure all water in both storages was removed before recommissioning the system - however doing this carries a risk of aerosolisation so there's a balance to be struck between the risks.  Heating the hot water cylinder to above 60 degrees should kill Legionella bacteria present, so that could be an alternative approach.


The other thing I'd take into account is if there is a cold water storage tank once this has started to refill it could continue to supply water to any defective pipework/fittings for a while, even after the main stop tap has been turned off - unless there are accessible and functional valves to isolate the tank supply to these pipes.  These valves (if fitted) often seize up and don't work when needed - so I would locate and test them before turning the mains supply back on.

If there are no such valves - or they don't work - that could be a good reason to call in a plumber to install (new) ones, and while they are to give the system a check.


If there is no bulk water storage then recommissioning is much easier - but don't forget storage in toilet cisterns, and the effectiveness of toilet flushing systems at aerosolisation.

There's a cold water cistern in the loft, feeding a hot water tank. That was my main concern, how long it would take to clear any puddled old water in the system. As the boiler won't be used until it's serviced, I'll make sure that there's a working... element(?) in the tank & it's set to 60/65.

The point about the cold water cistern is valid. Good thinking. I'll check but don't think there are any subsidiary valves anywhere. The only things that I can think of that would seize are the toilet flushes; it's a pretty small simple house. The cold water feed into the hot water cyclinder is presumably just a gravity feed, no valve? Is that how they work?

Could I close the ball valve inlet to the cold water cistern so it doesn't fill up, until I know the rest of it is all ok? Would that work?

I know that the motorised valve on the hot water will probably have gone; I've had problems with them before.

I'll be wearing a good mask & goggles, product of years of pre-covid healthcare but thanks for the point about the toilet flushes aerosolising.

Great info & thanks for all of this. Much appreciated. Will hopefully get it sorted in the next few week or two.

calvincamel

Bendy_House said:

Calvincamel, do you know what sort of DHW system she has? Is it a 'combi' boiler or a stored water system? If combi, then the issue is much simpler.

The only tweak I'd make to your own plan, is that I would not first open any tap before slowly opening the stopcock. I'd want to know if any water was flowing with the taps all closed. Any flowing water would either be down to refilling tanks - CWS in the loft, toilets, etc - or a leak. 

Once I was certain there was no sign of flowing water, then I'd slowly crack open each tap at a time and allow it to purge any air and the stale water. Obviously a 'coughing' tap will run the risk of aerosols, so a mask and standing well back would be advised at the very least. 

As already mentioned, the main sources of potential hazard are the water storage tanks, hot and cold. Your aunt is moving 'back' to this home, so did she have the system drained when she left (which would have been the wise thing to have done if she'd know the house would be left for this length of time)?  

How much investigation is she capable of doing - can she check the CWS in the loft, for example? Or do you know if it's a combi boiler - much easier to deal with?

 See above, it's a vented system(! I've learnt a bit from quick research) - boiler/cyclinder/cold water cistern.

With all outlets (taps, toilet flushes, cold water cistern) closed, air pressure in the pipes stop water from flowing freely, unless there is a leak - is that the idea? Anyway, it's an interesting idea, not one I've come across thus far.

House was someone else's, now deceased, but no, we don't believe the system was drained down.

It'll be yours truly who does any investigating, when I get a chance.

Many thanks for replying.

Section62

calvincamel said:

The point about the cold water cistern is valid. Good thinking. I'll check but don't think there are any subsidiary valves anywhere. The only things that I can think of that would seize are the toilet flushes; it's a pretty small simple house. The cold water feed into the hot water cyclinder is presumably just a gravity feed, no valve? Is that how they work?

Could I close the ball valve inlet to the cold water cistern so it doesn't fill up, until I know the rest of it is all ok? Would that work?

There should normally be manual valves to control the flow(s) out of the cold water tank - to the hot water cylinder and to anything supplied with cold water from the cold tank.  These valves would usually either be on the pipes where they exit the cold water tank, or somewhere in the airing cupboard.  But sometimes there are none.  On older properties they are likely to be either 'gate valves', often with a red 'wheel' type handle, or sometimes a traditional-style stop[male chicken] with a 'T' type handle.

If fitted, the valves are often useless because they have seized up and can't be turned off.  These valves being seized won't directly cause a problem as you recommission the system (they shouldn't leak), but if they don't work (or are missing) it does mean you can't use them for the purpose they are provided for.... i.e. to control water entering into different parts of the system.

E.g. if water starts pouring out of a hot water pipe, closing the valve supplying the hot water cylinder will stop the full contents of the cold water tank leaking out via that route.

It would also allow you to apply a more controlled and strategic recommissioning process - e.g. I would isolate the hot water system so the contents of the cold tank in the loft can be flushed out via the cold taps (only), rather than introducing (possibly) less clean water from the cold water tank into the hot water cylinder and pipework.

So if there are no (working) valves on the exit side of the cold water tank then I'd make getting some fitted a priority job - which could give you a good 'excuse' to get a professional in to do that (and checking the system over fully if that's what you'd prefer).


Closing the inlet to the cold water tank would allow you to check the 'mains' side of the system first - and that is a good idea - but it won't stop water which is already in the tank from leaking out if there are any faults on the 'low pressure' side.
 

calvincamel said:

I know that the motorised valve on the hot water will probably have gone; I've had problems with them before.

It depends on the condition of the valve to start with, and to a degree whether the central heating system was drained down.  I would make sure the electrical supply to the CH is off and then operate the 'manual lever' on the motorised valve a few times to make sure it is moving freely.


More generally - the point of introducing water into the plumbing system in stages is primarily one of reducing the scale of the disaster if something goes wrong - not just because it produces the conditions where leaks are more likely to be apparent.

E.g. filling the 'mains' side of the system (only) first - without letting water run out of taps etc - allows you to limit the extent of checking you need to do to those pipes.  Once you've proven that part of the system is OK you can move on to the next part.

If you tried to do everything in one go you could be in the position of (say) needing to stop water pouring out of a hole in the hot water cylinder at the same time as stopping water gushing out of the mains supply pipe in the loft.

The staged approach lets you concentrate on one part of the system - although always bear in mind it might take hours or days for some faults to become apparent, so rechecking is essential.