Plumbing Issue - Hot showers!

[ChrisDes]

Just a quick question to find out some info about a really annoying problem..

The property at the moment has beeen completely renovated. However the plumbing has one really annoying problem.

When having a shower, if someone else in the house turns any cold tap on or flushes to the toliet the shower immediately goes HOT! And remains hot until the tap is shut off - this problem is really annoying. It seems to be that the cold water flow is diveted from the shower to the tap that is turned on.

The water heating is through a Rheam Gas Storage Heater - it is heated up using gas and stores the hot water in the tank outside the house - it is very efficient and can reheat the whole tank in under 30 mins.

The same applies even when someone flushes the toliet etc - so you can imagine how annoying this is. How much would this be to fix? Assuming it can be - would this invovle re-plumbing the home or something similar?

A lot of money has been spent on the house which is:
-Aprox 45 years old
-Wiring renewed
-Full interior paint
-Full exterior paint
-Exterior plastered over summerhil stone
-New Kitchen
-New Bathroom
-New Gas Storage Water Heater
-New W/C
-Roof, some wall and floor insulation
-Double Glazed
-Halogen Lightening
-Heat Pump

It seems strange that the plumbig would be such an issue, especially when new water heating has been installed with a Rheam gas water sotrage tank - one that is installed outside the home.

Any help much appreciated

Regards

Chris

[SuperDad]

Sounds like the shower and other fixtures are in series, such that the shower is at the wrong end of the series. This would not have been fixed by installing the new heating system.

Perhaps the problem could be fixed by teeing off the main feed before the first fitting (e.g. toilet or kitchen sink) and feeding the shower from there? That way the shower takes priority feed.

Just a guess from a DIYer.

Paul.

[whitt]

SD Tee theory may work,

Another DIY guess.

My theory:
Find the end of series and bring back to start and make system a big loop. Providing it easy access. ( sometimes plumbing is simply clipped under floor beams). Then it just matter of running one pipe back to start and adding tee there.

It really depends on how many water fixtures the pressure drop is noticed on. Is it just one shower or several showers in the house.

Disclaimer:
This is all just theory and unproven. And simply a variation on the SD version. A loop would give pressure from both ends so if one side gets lower the change is minimal.

[SuperDad]

I did something similar to what whitt suggests with my pool, but slightly more complicated, to get even flow between three outlets from a single inflow.

[Wayne]

The problem is that the cold water pressure drops when another tap is turned on.

The cold water feed should be the same one that feeds the hot water tank. In this way, when a cold tap is turned on, the pressure drop will drop the hot water pressure (because the cold water forces the hot out) and the cold water pressure equally. You won't get a temperature change (or no where near the same) but will just get a flow change.

Any plumber worth his salt should have plumbed to allow for this.

[Perry]

One possible fix is to put a flow restricter into the
pipe to the toilet cistern and such. The speed at
which they fill (flow rate) is not as critical for such
ancillary fixtures, as it is for a shower.

Any idea what the water pressure is? Is there
a blocked filter, somewhere? If there are mixer
taps, it's often a warranty condition that filters
are fitted. Guess what? if so, they need cleaning,
every so often.

If a filter is present and not cleaned/flushed, flow
rates (not pressure) can drop drastically, causing
fluid/hydraulic problems. The shower is usually the
first casualty. (the person in it, to be more exact)

Some sleuthing may be required.

[ChrisDes]

Cheers for all the help, I've managed to get in touch with a plumber on Trade Me and he reckons it is just a flow restricter that was placed on hot in stead of the cold - so it should be a simple fix to change this around.

It also could be a blocked filter somewhere along the line as ChCh does have a silt type residue build up on water mains - especially in North West Chch where the house is located.

I'll let the professional plumber fix this one!

Regards

Chris

[Wayne]

Cheers for all the help, I've managed to get in touch with a plumber on Trade Me and he reckons it is just a flow restricter that was placed on hot in stead of the cold - so it should be a simple fix to change this around.

It also could be a blocked filter somewhere along the line as ChCh does have a silt type residue build up on water mains - especially in North West Chch where the house is located.

I'll let the professional plumber fix this one!

Regards

Chris

and pay through the nose no doubt. How they justify their $85+GST per hour I don't know.

[princess]

at least you have one.

i've asked four companies to quote a job, 6 weeks later i have just ONE quote and its about 4 times what i want to pay. Quote number two supposedly arriving today.

Tradespeople.

[Errol]

at least you have one.

i've asked four companies to quote a job, 6 weeks later i have just ONE quote and its about 4 times what i want to pay. Quote number two supposedly arriving today.

Tradespeople.

The rule is, find good tradesmen and stick with them, pay them promptly and thank them for their service. Works for me, normally they are there the next day, I phone and thank them as soon as I have checked the job, I then pay on invoice.
As to their charges, just be thankfull that it's not you under the floor, or replacing a toilet bowl.

[Re@der]

Good advice Errol. For me Plumbers are the most used tradesmen and I value the one that I use. I seek his free advice on all plumbing items. Pay by Internet immediately on receipt of email invoice and get great service.

[Wayne]

As to their charges, just be thankfull that it's not you under the floor, or replacing a toilet bowl.

been there - done that. Not so bad really. Maybe they could charge accordingly - costs $85+gst to change a tap washer or replace the toilet. Doesn't seem fair to me.

And don't get me started about the way they not only charge heaps but then they buy at wholesale and charge full retail (+ travelling time to get the bits they forgot). They hate it when you supply the goods - even if it is the same brand as they buy so can't say that the item is unfimiliar.