Bizzare Plumbing issue.

[sicca]

Hi there,

We have recently moved to a new house and it seems that we have a very odd problem with the hot water pressure in the main bathroom.

The house has a ground floor with kitchen (where a combi boiler is installed) and a cloakroom. In the basement we have the main bathroom.

The symptoms are as follows:

Kitchen - good hot water pressure
Cloakroom -good water pressure
Main Bathroom - no pressure at all, barely a trickle which I can actually stop when I place my finger on the tap. Because of this, the boiler doesn't get triggered (pressure is under the minimum 0.6 bar) so no hot water is produced. This is true for both shower and sink (cold water pressure is fine).

From what I can see, the hot water pipe runs from the boiler to the kitchen sink (about 2.5m) then it goes to the cloakroom (about 1m) and then it goes under the cloakroom floor and then trough a cavity wall, only to show up under the basement bath from where it is carried forward to the bathroom sink (it’s no more than 4m).

For the part where the pipe is visible, I have checked all the valves and they are fully opened but just wondering if there might be any other valves hidden from view by the floor/wall…

Unfortunately there aren’t any inspection points either under the floor or cavity wall and the only option I have been given is to take of the cloakroom floor which is a pig of a job to do .

Other things that I have tested:
- Mains water pressure coming into the boiler is very good, 1.8 bar
- Hot water pressure coming from the boiler is again very good
- Replaced the hot water tap on the bathroom sink to see if that would do anything but no change…

Any advice or ideas would be greatly appreciated before I go and rip the floor up .

 

[expertgasman]

Faulty tap, new headworks required, or is that too obvious and I'm missing something?

 

[sicca]

Both the bath tap and the sink tap have the same issue, it would be too much of a coincidence, but just to make sure I have fitted new taps on the sink and I haven’t seen absolutely any improvement.

 

[PlumbGas]

Both the bath tap and the sink tap have the same issue, it would be too much of a coincidence, but just to make sure I have fitted new taps on the sink and I haven’t seen absolutely any improvement.

could be any of the valves not open properly, they may look open but if they are old gate valves they may be broken in a not fully open position

 

[Agile]

Hi there,

We have recently moved to a new house and it seems that we have a very odd problem with the hot water pressure in the main bathroom.

If its really a new house then surely its the responsibility of the builders to sort it out?

Tony

 

[sicca]

Both the bath tap and the sink tap have the same issue, it would be too much of a coincidence, but just to make sure I have fitted new taps on the sink and I haven’t seen absolutely any improvement.

could be any of the valves not open properly, they may look open but if they are old gate valves they may be broken in a not fully open position

Hi PlumbGas,
All the service valves that are visible seem to work fine, what I can't find is any valves from the cloakroom to the bathroom downstairs. Surely any responsible plumber wouldn’t have buried them under the floor or partition walls.
I will take your advice though and replace the ones that I can see, hopefully that will make a difference.
Thank you for the advise.

 

[sicca]

Hi there,

We have recently moved to a new house and it seems that we have a very odd problem with the hot water pressure in the main bathroom.

If its really a new house then surely its the responsibility of the builders to sort it out?

Tony

Hi Tony,

The house is quite old and been converted to two maisonettes back in 2004. Sorry for the confusion, when I said "new house" it was because it's new to me .

Thank you

 

[Agile]

If its not really a new house and the cold pressure in the bathroom is OK but the hot flow ( not pressure of course ) is very poor then there seems to be a blockage then you could try to reverse flush it out.

Turn OFF cold into boiler.

Turn kitchen hot tap ON and join cold and hot in the bathroom and turn on hot and cold in the bathroom which should produce cold flow into the kitchen tap and just possibily might reverse flush some blockage out.

If not then some careful testing might be needed of the pipe resistances.

Tony

 

[PlumbGas]

Both the bath tap and the sink tap have the same issue, it would be too much of a coincidence, but just to make sure I have fitted new taps on the sink and I haven’t seen absolutely any improvement.

could be any of the valves not open properly, they may look open but if they are old gate valves they may be broken in a not fully open position

Hi PlumbGas,
All the service valves that are visible seem to work fine, what I can't find is any valves from the cloakroom to the bathroom downstairs. Surely any responsible plumber wouldn’t have buried them under the floor or partition walls.
I will take your advice though and replace the ones that I can see, hopefully that will make a difference.
Thank you for the advise.

when replacing valves try to use 1/4 turn full bore lever valves, if you have to use gate valves use Pegler

 

[sicca]

If its not really a new house and the cold pressure in the bathroom is OK but the hot flow ( not pressure of course ) is very poor then there seems to be a blockage then you could try to reverse flush it out.

Turn OFF cold into boiler.

Turn kitchen hot tap ON and join cold and hot in the bathroom and turn on hot and cold in the bathroom which should produce cold flow into the kitchen tap and just possibily might reverse flush some blockage out.

If not then some careful testing might be needed of the pipe resistances.

Tony

Thanks for that Tony,

I'll add this to my list of things to try for tonight. Hopefully it will cure the problem.

Sicca

 

[holty]

as mentioned sound like a blockage or even a kinked pipe that has been knocked or damaged or even an old valve that was previous to the combi fitted. do you get a good spurt of water from the tap when turned on, then fades to a trickle?

 

[sicca]

as mentioned sound like a blockage or even a kinked pipe that has been knocked or damaged or even an old valve that was previous to the combi fitted. do you get a good spurt of water from the tap when turned on, then fades to a trickle?

Hi holty,

No there is no spurt coming out when first turned on, it just comes as a trickle all the time.
I'll try and see if I can flush the system, but as you say there might be a dent somewhere along the lenght of pipe that is hidden behind the walls/floor, in which case it will probably need some professional attention

 

[sicca]

Hi Guys,

Thank for the advice. I have actually tried flushing the system as per Tony's instructions and had no luck. When running water from the Cold tap to the Hot one in the bathroom (an yes the hot one was open as well ) I wold get the same trickle of water coming out in the kitchen or cloakroom which would confirm that there is something wrong with the pipe.

I actually went farther and removed the cloackroom floor (good thing I did as parts of it were completely rotten) to expose the pipes but could not see anything out of the ordinary. There is a small dent on the hot water one, probably when they've fitted the floor but I wouldn't imagine that this would cause the issue. There are also no other valves between the cloakroom and basement bathroom so it all looks like there is something stuck maybe inside the pipe...

I think the cheapest way to probably fix this is to cut off the lenght of pipe from the cloackroom to the bathroom and have it replaced with a new one, unless anyone has a better idea.

 

[Onetap]

Hi there,

Main Bathroom - no pressure at all, barely a trickle

Two things I came across that were causing the same problem.

The first was service valves, reduced bore ball valves. The waterway narrows going through the ball, which isn't normally a problem. On this one house, there was no lid on the cold water storage tank and bits of mineral fibre loft insulation had got in; this blocked random ball valves. Easily cured, once you knew what it was. Remove service valve, blow clear, refit. There are sometimes mesh strainers on tap outlets which can also get blocked.

The other was similar, but involved a bit of foam insulation from the HW cylinder which had got into the cylinder. Numerous people had dismantled the bath taps trying to find the fault. Draining the water, to dismantle the taps, caused the water level in the pipe, with the foam lump floating on it, to drop out of sight. Turning the water on caused the foam to block the tap inlet. I found it by running a trickle of water into the storage tank with the tap dismantled, allowing the water to overflow out of the hole in the tap body; the foam bobbed up and was hooked out. The bloke thought I was psychic and paid me double.

 

[sicca]

Hi there,

Main Bathroom - no pressure at all, barely a trickle

Two things I came across that were causing the same problem.

The first was service valves, reduced bore ball valves. The waterway narrows going through the ball, which isn't normally a problem. On this one house, there was no lid on the cold water storage tank and bits of mineral fibre loft insulation had got in; this blocked random ball valves. Easily cured, once you knew what it was. Remove service valve, blow clear, refit. There are sometimes mesh strainers on tap outlets which can also get blocked.

The other was similar, but involved a bit of foam insulation from the HW cylinder which had got into the cylinder. Numerous people had dismantled the bath taps trying to find the fault. Draining the water, to dismantle the taps, caused the water level in the pipe, with the foam lump floating on it, to drop out of sight. Turning the water on caused the foam to block the tap inlet. I found it by running a trickle of water into the storage tank with the tap dismantled, allowing the water to overflow out of the hole in the tap body; the foam bobbed up and was hooked out. The bloke thought I was psychic and paid me double.

Hi Onetap,

Thanks for the advise, unfortunately I've got a combi boiler so there's no water storage tank or HW cylinder and again there are no service valves (none that I can see) between the cloackroom and the bathroom downstairs. There is definately something lurking about in that lenght of pipe but God knows what it is.

In the meantime could anyone recommed a reliable plumber in the Reading area?