Water Hammer has burst my coupling

[iwaters]

I built a new en-suite recently. The old shower wasn't thermostatic and was very old - never had any problems with water hammer.

The new shower is thermostatic and I had been suffering with water hammer both when turning on and off. I tried to negate it by turning the shower on and off slowly. However it still happened occasionaly and it is has now burst the connector on the shower.

Now its all tiled I can't access the pipes from the bathroom so will have to cut a big hole in the plasterboard from the stairs and access them from behind.

Think it is time to call a plumber and get the pipes installed properly. I don't know what I have done wrong so don't know how to fix it. The plubmer is probably going to think I am a right prat!

 

[yerino]

Did you clip the pipes?

Did you fit isolating valves to reduce the pressure?

 

[Johnmelad]

Did you clip the pipes?

Did you fit isolating valves to reduce the pressure?

Shoulkd isolating valves be used to reduce pressure?

 

[Dan Robinson]

They won't do squat for pressure, but there are flow reducing valves.

 

[Agile]

Non return valves might also be a good idea on the hot supply. Probably asked for in the instructions.

Why do people tile over plumbing fitments?

Tony

 

[onlyfitidealboilers]

Fit an expansion vessel to your cold water main

 

[Charnwood]

Fit an expansion vessel to your cold water main

Or a water hammer arrestor.

 

[foxhole]

Push fit connectors? they jump off with water hammer, replace with compression.

 

[iwaters]

Thanks for the replies. The connection that burst is the compression fitting on the shower mixer. There are no compression fittings that have been tiled over, but the pipes have so I can't easily access them to fit a shock arrestor.

The pipes were clipped but I suspect not enough. I will cut an access panel and fit some strapping to clip the pipes to and fit an arresstor. How reguarly should the pipes be cliped?

The instructions made no mention of a non return valve.

I fitted gate valves instead of isolating valves because none of ths isolationg valves I looked at were full bore and I didn't want to restrict the flow. Also I would have thought that adding a restriction like that would increase the presure?

The worse hammering is when the mixer is switched on, I guess this is where the thermostatic mixer is trying to regulate the temperature and is swtiching the supply on and off.

Also when I bent the pipe to 45 degrees the spring wasn't lined up correctly and the pipe kinked slightly, could this be having an effect as well?

 

[bhm1712]

http://www.screwfix.com/p/honeywell...ducing Valve&gclid=CID5gKnep60CFYEmtAodEnarWA

 

[Johnmelad]

http://www.screwfix.com/p/honeywell-15mm-pressure-reducing-valve/85889?cm_mmc=Google-_-Datafeed-_-Heating%20and%20Plumbing-_-Honeywell%2015mm%20Pressure%20Reducing%20Valve&gclid=CID5gKnep60CFYEmtAodEnarWA

 

[bhm1712]

its a pressure reducing valve......15mm.

 

[Nige F]

Now its all tiled I can't access the pipes from the bathroom so will have to cut a big hole in the plasterboard from the stairs and access them from behind.

Think it is time to call a plumber and get the pipes installed properly. I don't know what I have done wrong so don't know how to fix it. The plubmer is probably going to think I am a right prat!

Nothing wrong with an acces panel in the stair wall So what if the plumber thinks anything

 

[Nige F]

flow. Also I would have thought that adding a restriction like that would increase the presure?

The worse hammering is when the mixer is switched on, I guess this is where the thermostatic mixer is trying to regulate the temperature and is swtiching the supply on and off.

Also when I bent the pipe to 45 degrees the spring wasn't lined up correctly and the pipe kinked slightly, could this be having an effect as well?

slightly kinked pipe is no problem - have you got unbalanced supply pressures hot from a copper cylinder + mains cold I`m struggling to see why a shower mixer would hammer with low pressure tank fed supplies

 

[iwaters]

flow. Also I would have thought that adding a restriction like that would increase the presure?

The worse hammering is when the mixer is switched on, I guess this is where the thermostatic mixer is trying to regulate the temperature and is swtiching the supply on and off.

Also when I bent the pipe to 45 degrees the spring wasn't lined up correctly and the pipe kinked slightly, could this be having an effect as well?

slightly kinked pipe is no problem - have you got unbalanced supply pressures hot from a copper cylinder + mains cold I`m struggling to see why a shower mixer would hammer with low pressure tank fed supplies

The hot water system is a unvented megaflow cylinder, the mains pressure is very high and hot water is at the same pressure.