Hot Water Pressure Problems

[DarrylF]

Moved into our new (25 year old) house last weekend, so I'm fixing all the issues the previous owners had just lived with :)

Main remaining issue is the hot water pressure. The system is an Edwards solar system, installed 3 years ago. Temperature is just fine, electric boost works like it should.

However, the hot water pressure is much lower than the cold water pressure. We also are getting some hammering in/around the non-return valve.

Local plumbers supplier suggested the trick with deforming the shaft of the washer in the non-return valve, but first try I couldn't get the thing unscrewed. Will try again tonight.

The setup has a non-return valve, followed by a 500kpa pressure limiting valve, followed by a 700kpa pressure relief valve. After that there is a cartridge water conditioner. All are located in the laundry and look to be in reasonable condition.

I've checked the water conditioner cartridge & cleaned it up (has a type of rock-like crystals inside). I've re-seated the taps & put good washers in. Not sure what else to try at this stage.

When running the shower we get a hammering around the non-return valve, which varies in pitch & intensity according to the position of the tap on it - sometimes we can eliminate it but usually not.

Any tricks to getting at the washer in a non-return valve? Is the constant mild hammering likely to cause the reduction in pressure?

Any other thoughts on what to check here?

[outback]

Poor bastard. Every sucker is looking, but no-one has any ideas.

I have lots of ideas.


But first, your problem.

Can you eliminate, washers from taps, elements from filters, by-pass stuff to isolate the problem.

But I reckon the non return is also limiting your pressure.

NO, don't thank me, I have been no help whatsoever, but you did get excited when you saw it was me who had replied. Admit it. :p

[Cliff Rogers]

Outback, you are a gem. Now farq off & leave the poor bugger alone. :D

I agree in as far as that what ever is causing the restriction is also causing the hammer BUT... in may not be where the niose is appearing to come from.:cool: You have to keep looking. ;)

I also haven't been too much help either BUT... if you offer us enough, (beer, wine, BBQ steak, money, etc) you could have the ever-so-helpful Outback & my good self (& half a dozen other kind souls) come & stay at your place til (we help) you figure it out. :D

[DarrylF]

There's always one in every crowd as they say.

Lucky me, I got two :D

Failing any better ideas I'll rip the lot apart and inspect the guts of each device in turn. Sounds like a Saturday morning job while the women of the house are at tennis & not complaining of having no water :)

[Zed]

Darryl,

1) Get Ceramic washer taps on all taps - pricey but ferking good. - you'll never look back.
2) get hammer arestors from the local plumbing suppliers - the type that you pump in air with a bike pump are the best. install 2 or three of these under a few sinks, in the pipework (where you can pump more air in as needed - ie acces) and you should be right.

dont deform the shaft of the washer - thats bullsheet. use arrestors on either side of the non return valve, i reckon the supplier uses that story to all the "non plumbers" who lob into his shop - ive NEVER seen that little trick work.... I was once told to strengthen the spring in the return valve so it would stop the hammer - that dont work either 0 it just loosens the pipes more as more energy is stored and released quickly (see below paragraph)

hammer is caused by the momentum in the water (water has mass right ?) coming to a sudden stop when you turn the water tap of and the energy in the water stored by momentum and mains pressure has nowhere to go so it moves the pipes (Newtons 3rd law - the conservation of momentum states every action must have an equal and opposite reaction) thus when the water stops moving the energy built up must be released, ergo, the momentum is released by a energy wave in the water bouncing the pipes - points of weakness like where the lousy plumber didnt use enough attachments in the walls can and do move - short of tearing down your walls and putting in more anchors you cant fix it - just compensate with arrestors which absorb the energy (they are "in line" attachments - sorta like series rather than parrallel as in electrical ccts.) thats why cement walled houses have bang in the floor and rthe ceilings and gyprock have it in the walls (thats where the pipes that CAN move are!

Here endeth the lesson :D

That should help you.

cheers

[DarrylF]

Thanks Zed.

Slightly off track though :) It's not hammer in the way you're thinking - it's kind of like a constant vibration from around the area of the non-return valve. It sounds like the problem the plumbing supplies guy was pointing to - the washer inside the non-return valve vibrating back and forth.

I'm not a fan of half-arsed solutions - we've just bought the place and we're planning to live there for years, so I'd like to fix it right. So should I just replace the non-return valve and be done with it (hopefully)?

[silentC]

So should I just replace the non-return valve and be done with it (hopefully)?
That would be a good start ;)