Hot taps

lorraine farrel

Just trying to find out if when I turn on the hot tap in the bath and then the hot tap in the sink, one of them stops working, is this right?

JohnnieK

Hi Lorraine

This is not right. The pipes are undersized. The bath would have a larger draw off that the WHB. This symptom is a classic sign of pipe under-sizing. The pipe is not big enough for the flow rate needed for the two fixtures to operate at the same time. If it is a modern house you live in this is a common problem because Installers didn't give a s***e and just horsed the pipes in to get it done on the cheap.

lorraine farrel

would the undersized pipes cause no water to be supplied to the shower bath and basin up stairs but yet downstairs all taps worked ok along with the toilets working ok. its an old house that has been re-plumbed. is there any law to say what size pipes need to be used or anyone i can complaint to
thanks

Eire-Dearg

I think it's a pressure problem. Where is your water storage tank situated?

lorraine farrel

the water tank is in the attic, the size on the side of it said 49/35 if that makes sense to you. the plumber told us it was to small that we needed a bigger tank

Eire-Dearg

How many bathrooms/showers is off this?

I think you are working off a problem called negative head, which means the pressure from your storage tank up to your bathroom upstairs isn't sufficient.

Micky Dolenz

Unlikey it is a negative head problem, if so, you would not get any water at all, unless pumped.

It is not normal. You have a lack of water, either a valve is partically closed. a pipe is blocked or kinked under floor or as Johnnie has suggest, the pipes may be undersized.

JohnnieK

Dose the water work up stairs when nothing is running down stairs?

JohnnieK

The size of the tank with this problem is irrelevant, that's just storage capacity. It's possible the plumber brought 3/4" pipe to the bath and 1/2" pipe for every where else so save on costs. It is impossible to know with out seeing. If the water is ok when nothing is running down stairs but stops when something is, then I would be looking at undersizing.

Joey the lips

Is there a chance the taps were replaced recently. ie did this happen before and since taps were replaced it has stopped. To me assuming all things being equal it sounds like a pressure problem.

Describe your pluming in detil. ie house/apartment pump/no pump new taps. different taps than orig how long as problem being happening

kaizer13

As you have a header tank in the loft, then I assume that you have a hot water cylinder in the hot press. If you have recently had plumbing work carried out that neccessitated the shutting off of the hot water, then your system may have been left with a broken gate valve in partly or even nearly fully closed position. The gate valve is usually a round handled valve that controls the cold feed (larger diameter pipe of the two sizes usually found in the hot press) to a connection near the base of the cylinder. These valves, particularly if made within the last twenty years or so are usually of feeble internal construction and the gate valve, by design is prone to internal fouling of the mechanism by limescale. An over exuberant plumber in their attempt to fully shut off cold feed to the cylinder (and consequently hot flow from the taps) can easily strip the threads within the gate valve. This can result in a valve that is no longer able to be fully opened, the result is a starvation of flow to a system that may have been perfectly ok before. The only remedy in this case is to fit a replacement valve and I recommend a lever operated, full bore, ball valve as these are much less likely to fail than a gate valve.