So a plumber came in to supply hot and cold water to a downstairs room. He popped T-junctions (white pipes heading west) in to the hot-cold water feed to the shower upstairs (grey pipes heading north). Hot and cold is fine to the downstairs room.

[url=https://flic.kr/p/2kRyYMR]20210407_070938[/url]

But the shower is permanently cold. If I cut off the cold fee to the shower, hot water comes out but as soon as cold is turned back on, no hot comes out. And, when the shower is running, I can feel vibration in the hot feed pipe so assume water is moving a bit.

Pre this, the shower was perfect. Any ideas – the plumber is stumped and now seems to be uncontactable! Much as cold showers are refreshing, a warm one would be lovely too!

I’m not sure what the problem is but that pipework is shocking.

Get someone else in.

Where does the hot water come from?
Gravity fed or mains pressure?

What kind of valve on the shower? And what’s the pressure like on the hot water to the shower when it does come out. Furthermore – how cold is the shower when the cold feed is on?

has he cut the pipe and put the wrong ends into each end of his Ts ….. but connected his new pipes correctly to the new shower

IE has he now got a cold feeding the hot side of your upstairs shower ….

Or do you need a 1way valve is the cold pushing the hot water back?

Oh and that’s rough as F…..

Has he connected them back the wrong way around for the shower?

ignoring the rough pipework, my money is on one of the showers passing cold water through from the hot pipe side due to a pressure difference in the system. some one-way valves in there would help eliminate this as a cause, (put onto both showers) .

Depends what type of showers you’ve got one each set up

I’m a DIY plumber and I’d have done a better job than that, it’s awful. Looks like he’s used the cheapest push fit stuff as well.
I’m not surprised he’s in a pickle as I’m not sure he knows what he’s doing!!

wot trail rat says

Wow, thanks all. I’m not a plumber but do a bit of DIY and I was a bit disappointed with the work as it looked like I had done a bodge job!

– hot water comes from a main tank just below the pipework in the pic
– cold in the shower feed is very cold
– hot water in the shower now (when cold feed turned off) is sluggish, albeit I don’t know if this would be normal
– I tried switching the grey pipe feeds around for the shower, but no difference. trailrat – I don’t think I’ve done exactly what you’ve said though so will look at that
– no 1 way valve installed but that sounds like a likely solution that the cold is over-powering the hot (to an ignoramus like me!) as the cold is pretty powerful. I’ve tried turning the mains pressure down tho and no difference
– the new pipes run to a sink in the downstairs and work ok

Thanks all, reassured me a lot and for my wife, maybe good info that he’s a nice chap but not a plumber!

I’ve tried turning the mains pressure down tho and no difference

Unless you fit a proper device all you are doing is restricting flow and therefore pressure in a non linear way

the easyish way to test would be to see if another hot tap nearby starts to go cooler once the shower is turned on. If this is the case, you should (I think) normally have a cold water tank as well, so a fix would be to take the cold water from there, not direct from the higher pressure mains feed.

Either way, find a new plumber. that guy is bodging it. You might need a pump to get the pressure up

I would try reorientation of the T

Also fit a controlling valve on both feeds, I can’t understand why people don’t fit them

The safest way is to get a proper plumber in.

Do you have an unvented system, as the tank looks quite tall, which is common with them?
If so, there are a few things that can go wrong as there is a sequence to re-charging most unvented systems.

As a check, you could try plugging up the new pipes he’s put in from the tees and see if your shower then works again as it used to. The push in plugs are readily available but you’ll need to isolate / turn water off to mess with it (sorry for the obvious safety point)

Even if you get it working, I’d suggest you neaten that hose work up and fasten it to something solid at least.

I wonder if a sliver of plastic* has been washed up into the shower valve?

*Looking at his “work” I can imagine a scenario of a wonky knife cut being straightened up.

We have a pressure balancing valve for our shower. It makes a whirring noise on shower start up as it does its thing.

When we had our pipe joint burst a couple of years ago I tried to plum the shower without it – and it was like yours basically cold. Put valve in and it works.

Maybe the hot water flow rate was at the outer edge of the range for the shower, and adding the t junction in the pipe has reduced it below working range for the valve.

Since you can get hot water out when cold it turned off, you could measure the hot flow rate (by timing filing a container). Similarly you could measure the cold flow rate.

In you could find specification for shower valve you could see if in range.

Might also be worthwhile measuring flow rate at new hot tap downstairs.

Assuming it worked before, it can’t be water pressure as nothing has changed in that regard.

My bet would be he’s introduced a bit of swarf cutting the pipe which has blocked the thermostat valve in the shower.

Even if you get it working, I’d suggest you neaten that hose work up and fasten it to something solid at least.

Sticking some isolating valves on your new and shower feeds will save you a bit more aggro down the line too.

Given the state of that, I’d be worrying about whether he has used the correct inserts in the plastic pipe junctions.

Given the state of that, I’d be worrying about whether he has used the correct inserts in the plastic pipe junctions.

Assuming you are at mains pressure and that mains pressure isn’t pants .

He would know about it already based on my experience at considerably less than mains pressure……… You only forget an insert once 🙂

I’m fairly sure that I only had a cold water feed when I had a shower fitted at the old house.

I’m not sure what the problem is but that pipework is shocking.

Get someone else in.

This should’ve ended the conversation really. You didn’t pay him, did you?

I’m fairly sure that I only had a cold water feed when I had a shower fitted at the old house.

for an electric shower yes….

Sounds like the hot and cold feeds are the wrong way round to me, but think the OP has covered that.

Aha.

If there’s no flow in the new pipes it’s the same as before they were put in (well, very small pressure drop due to the tees.)
So as above, either on the edge of working before or a large bit of pipe where it shouldn’t be.

Is it a thermostatic shower mixer
They have mesh grids on the inlts and a tiny bit of copper, ptfe or grit will drop the flow right down
Or its a pressure balance difference causing zero flow from the hwt
I guess its an unvented cylinder

Why dindt he do the cut and shut higher up and fix to the ceilingvwith a pipe clip

I thought you only needed inserts on hw side, otherwise clean cut, de burr leading edge and insert fully. Bit of silicone spray then pull back to seat the o ring

need help so does our plumber

Your plumber doesn’t need help, he just needs to learn how to be a plumber. That work is shocking.

Thanks all, pretty consistent response. So for a bit of context – it’s a young(ish) lad who is going it on his own; came around, v polite, quoted and we had heard he was ‘lovely’. Keen to give young guys a chance. But, I guess he’s starting out on his own a bit early. he’s just messaged us to say he’s bringing an experienced plumber around to check it for us, so giving him the benefit, and I’ll not mess with it/call in anyone else until he has the chance to get it right.

But lesson learned, albeit we where all young once (although the more I look at it, the more I realise how rough and ready it is)!

Everyone has to start somewhere.

Least he is coming back n not just running away. Which already makes him more reliable than half the trades I’ve dealt with.

Hopefully his mentor will point out the difference between functional and tidy job.