Thread: Instantaneous Hot Water System

Let me first say I'm not a plumber.

Where did you get the idea that the gas mains needs to be changed?

Call a plumber and they will inform you of what's required.

Replacing the gas mains because a new appliance is acquired, does not seem "on the money".

The “mains” is a meter with an on/off valve.

As to the size/diameter of the gas pipe to the hot water unit, Rheem as well as any GOOD plumber should be able to tell you the right size for the distance.

I would get a second opinion on pipe size.

As for technical knowledge and manual labour required, this is not difficult.

Could you do it, unlikely.

Are you allowed to do it? by law NO.

As for cost, who could say; very rough guess;
quote the plumbers cost at $80 an hour; have a guess how long he should spend.
The pex pipe at $5 per metre + $100 for fittings.

Now is it worth doing yourself? Gas leak? Water leak?, Void warranty.

Anyway good luck

Pulpo

Originally Posted by Cobber

Just bought a aRheem Integrity 26 for my house....apparantly I need to change the gas main and make it a wider pipe so it works. Anyone know the cost of this or how complicated it is. I imagine a plumber needs to do it also.

When I was replacing our HWS I looked into buying one of those units and wanted to place it on an outside wall right next to the gas line running up to the ducted heating unit. This was the closest to the bathroom and existing pipework.

I was advised that I would need to replace the gas line up to the hot water unit as the diameter of the existing gas line ( 3/4 " ) was not large enough for the gas flow needed ( 1 1/4 " ) for these type of units.

This is probably what you are told and could be rather expensive. In my case the cost of the unit and the installation would have been twice the cost of a normal mains pressure electric HWS. So I stayed electric.


Peter.

My plumber told me the same thing, changing the pipe diameters.

As part of our renos (refer to other thread) we moved and upgraded the gas meter. Plus installed a Rinnai 26 unit along with new pipes.

The cost for the moving and upgrading of the gas meter was under $400, the Gas company did that. We weren't required to upgrade the meter for the Rinnai, but we had to move the meter and therefore took the opportunity to upgrade it.

The installation of the Rinnai, plus about 10m of new 25mm pipes was $1800. But this included reworking of existing pipes and system through the house as well.

Best estimate: Installation $500 Upgrade of Meter around $400.

Either way for us, it was a great decision the old HWS was electric and expensive. The new unit is much more efficient and we are saving money. But it is horses for courses. As for installing yourself, only if your a plumber!!

Just make sure you get a couple of quotes to give yourself an idea of what your up for.

Cheers

Thanks everyone. Yes you definitley need a wider pipe.

$400 sounds good. Which Gas company did it for you then Namtrak?

The builder has agreed to install the HWS (their plumber) so wont pay installation fees which is good.

Origin Energy I think. Who is your local supplier? Just contact them.

Hi Cobber

We replaced our instant system last year for a new one too. When it was installed, the plumber said the same thing, but we (on his 'unoffcial' advice) decided to give it a go on the diameter already there. He did warn us that there was a 1 in 20 chance that his work would be audited, and that the offcicial plumbing body would make us upgrade (even if it worked fine).

Anyway - bottom line is that the system works fine, no problem, no further money.

Cheers, Justine

Cobber

I would be very surprised if you had to change the gas main from the street to the house. Are you sure that is what the plumber meant?

I recently had a Rinnai instantaneous hot water service installed and the plumber had to fit a new 20mm copper T off pipe at the meter to connect to the Rinnai because the previous storage hot water service only had a 3/4'' galv. connection and the gas volume per minute was inadequate for the new hot water service.

Regards
Trevor

Trevor Im sure thats what it is. Hoe much did you plumber charge you for that. I reckon form the meter to the HWS will only be about 4 metres in distance.

We had gas installed to the house for three loads....you should see the meter go when all three appliances are going!

188mj Rinnai 24
98mj? Braemar central heater
65mj gas cooktop

The gas company contractor ran 19mm poly pipe to medium pressure gas main and installed medium sized meter.

My gas fitter then fitter 11/4 inch pipe to the first take off point..then dropped to 32mm then dropped to 25mm. All take offs are in 25mm pipe.

All up cost was $900 to supply and fit all copper connections.

I had to do the same thing when I installed gas CH and a rinnai infinity 26, the existing meter was not up to the task. The gas company (Origin Energy) replaced it at no cost with a larger new meter (I just had to give them the plumbers job number and the plumbers estimate of MJ required, he said to tell them 360-400MJ to get a meter with some headroom) , plumber did the new pipe. All of a sudden we had proper pressure on our cooktop jets, there was no way I could have gone from cooktop only to cooktop, hot water and central heating on the existing system. Supply and install the rinnai, put in new copper pipes with fittings ready for the central heating, approx 25m of 32mm copper with 19mm offshoots was around $1600. Not bad considering the hot water unit retails for $1200.

Cheers
Ben

Sorry Cobber, can't say as it was part of a complete bathroom reno.

Regards
Trevor