No cold from shower mixer

[Ray]

We've just connected the shower mixer to the hot and cold supply pipes.

 

We have found a slight leak on the cold inlet supply connection to the mixer (so we know water is getting thus far). However, when we turn the mixer on and off, we only get a very slight dribble of water. The story is the complete opposite on the hot side. We open the valve on the supply side of the mixer and, no matter what position the mixer control is in, we get water from the output side. We can control the flow slightly with the mixer but we can only stop the flow if we close the supply line valve.

 

The cold supply is fed direct from the tank, through the water pump and an accumulator. The hot supply is taken direct from the calorifier which, in turn, is fed from the same cold supply that the shower uses. There is cold water to the supply valves for the bathroom wash basin tap and the kitchen sink tap - we haven't fitted these taps yet.

 

Has anyone any bright ideas? The shower is a basic Screwfix one, nothing too posh. It is also the only thing that we didn't test when we fitted it originally (for a good reason) and it is now hidden behind a false panel and cannot be removed without some fairly expensive dismantling of the boat - don't ask, the story's too long! It is also the only thing that we can't easily get to, even if we could remove it.

 

Ray

[Gary Peacock]

This might be obvious but you haven't reversed the hot and cold?

[ChrisPy]

I know you say it is inaccessible, but you have to cure that. There are usually gauze filters on each inlet that may need occasional cleaning.

 

You should uncouple the pipe connections and check there are no blanking washers where the gauze filters should be, or that the gauze filters are not blocked with crud or PTFE tape?

[Boaty Jo]

mixer knackered?

[Ray]

We certainly haven't reversed the hot and cold, having been very careful with the positioning to make sure that we avoided that. We can get to the connections, with some difficulty, if needed, we just can't remove the body of the unit without dismantling the shower compartment.

 

We did check for internal obstructions before it was fitted, and didn't find any. We're off to the boat now and have a couple of ideas of our own to experiment with before we get desperate and call the manufacturer.

 

Thanks for the suggestions.

 

Ray

[wonderdust]

We certainly haven't reversed the hot and cold, having been very careful with the positioning to make sure that we avoided that. We can get to the connections, with some difficulty, if needed, we just can't remove the body of the unit without dismantling the shower compartment.

 

We did check for internal obstructions before it was fitted, and didn't find any. We're off to the boat now and have a couple of ideas of our own to experiment with before we get desperate and call the manufacturer.

 

Thanks for the suggestions.

 

Ray

 

is the pump kicking in when either of the hot / cold is opend

[Ray]

Thanks everyone, the problem has been sorted - let's call it operator error!

 

As supplied, the shower unit is designed for surface mounting (pipes and all). We wanted the pipes hidden, so we had to change the way the shower is assembled - the instructions with the unit are next to useless as they don't even tell you how to do that, even though the relevant accessories are supplied.

 

Either when we dismantled it or when we re-assembled it (and were trying to work out how the set it up) we appeared to have rotated the fittings on their respective spindles. Without the controls on properly, the spindles will rotate and rotate. With the controls on properly, the spindles won't rotate a full circle - as we would expect.

 

The operator error element boils down to us not appreciating fully what each of the two controls were doing - one appears to control the mix (on the input) and the other the flow (on the output). With the mix control not set up properly, the hot was able to flow, but the cold wasn't. It was not helped further because we were operating the flow control and thinking it was controlling the mix.

 

Now that we have reset the controls, we get hot and cold water and can control it - well, at least we think we do/can because the gas is off at the moment so we can't be certain as we can't heat the water. What we did instead was to control the input by our isolating valves, so only water from the hot or the cold supply was entering the fitting and we made sure that we could control the output as we thought it should be. We're running the engine for a while tomorrow, so we should have some hot water afterwards, so we can do a more thorough test.

 

Thanks for all the help (as always).

 

Ray