C/Van Hotwater System Maintenance

Submitted: Wednesday, Nov 28, 2007 at 18:19

ThreadID: 52059 Views:4793 Replies:3 FollowUps:3

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PeterInSA

2 years after I should have checked and replaced the anode in our caravans hot water system I have got around to doing the replacement. The old anode was just a piece of wire connected to the hexbolt. I know it should have been checked earlier but subconsciously I incorrectly thought that since we did not use the caravan/hot water system a lot, I had time on my side. This of course is grossly incorrect. The anode needs checking yearly. (I change the anode in our house gas hot water system every 5 years without fail so the need to do the job is not foreign to me)

So now I have a new Anode and a “How long will it last” Hot water system. Next year we plan on doing a couple of big trips in one instance up to 600km from the nearest large town for over 2 months. If the hot water system springs a leak with the water pump keeping pressure up to the whole system, to use hot or cold water the pump will continually flood the van via the hot water system hole.

My reluctant solution to this when it happens: I will have previously purchased a water pipe stop nut. I will disconnect the water line to the hot water system and screw in the water pipe stop nut. Will be then able to use pressurized cold water in the van again.

Even if you check/change the anode on a regular basis if you plan on being away from hot water system support for any length of time and your hot water system is x years old, if may be a good idea if you have a back up plan just in case.

Incidentally noticed a basket of Anodes on the desk at Camec Brisbane for $20 each. In Adelaide they are around $30 unless you get 20% off during a stock sale.

Peter

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Reply By: Mr Fawlty - Wednesday, Nov 28, 2007 at 18:45

Wednesday, Nov 28, 2007 at 18:45

Hmmmmmm as an expert in pressure vessels, I have plenipoteniary powers in the ACT, I agree that an annual check is all that is required replacing the Anode as needed. The anodes can last for years in situations where the water is "soft". I reccomend draining your HWS if not in use or otherwise keep it filled but turn off the water when the HWS is hot, this removes most of the free Oxygen in the water that cause corrosion.

AnswerID: 274091

Reply By: Redback - Wednesday, Nov 28, 2007 at 19:05

Wednesday, Nov 28, 2007 at 19:05

Can you explain the anodes job in the hot water system, ours stopped working on our last trip, i'm trying to find out why??

Baz.

AnswerID: 274095

Follow Up By: PeterInSA - Wednesday, Nov 28, 2007 at 20:06

Wednesday, Nov 28, 2007 at 20:06

Redback,
My understanding is that its like electro plating. If two dis similar metals are placed together eg Stainless steel and Aluminium in air(moist air) a current passes between them and the Aluminium is plated on the SS.
In the case of the hot water system. The metal from the Anode is plated onto the Tin box of the hot water system rather than say the metal of the Tin box holding the water being plated onto the heating element for example.

No Anode, the tin box metal gets thinner then holes, then leaks.

How do you know it stopped working, at this is a very slow process, I would not expect you to see any changes with the naked eye in a month. Then again I am no expert on the subject.

Peter

FollowupID: 537565

Follow Up By: Redback - Thursday, Nov 29, 2007 at 07:25

Thursday, Nov 29, 2007 at 07:25

OK thanks, mine isn't activating the burners, the pilot light is on but once the water is flowing it won't ignite the other burners to get the water hot.
I'm thinking the water flow isn't good enough to ignite the burners, might need to upgrade the pump or get a better flowing shower head.

Baz.

FollowupID: 537634

Follow Up By: PeterInSA - Thursday, Nov 29, 2007 at 12:07

Thursday, Nov 29, 2007 at 12:07

Redback,
I do not know your Hot Water system but I think you could prove whether it is the pump and associated equipment or not by supplying the water to the Hot water system via the mains. ie Connect up a garden hose to your mains connection, turn the hot water tap on, water at mains pressure will go thru your Hot Water system and if it gets hot it could well be the pump etc, if the water does not get hot its most likely something else.

I think that in these systems there must some sort of pressure valve that controls the gas flow to the big burners in the hot water system and it could go something like this:
. No hot water taps on, hot water line under high pressure,
. Pilot flame going.
. Turn Hot tap on,
. Pressure drops in the Hot water lines, pressure solenoid
comes in and opens gas line to the big burners.
. Pump starts to operate to supply cold water to the System.
. The big burners with the open gas line via the solenoid,
heat the water

Redback I am no expert in this area, but this would appear to be a logical explanation, so in other words your problem could be some form of water pressure switch.

Of course working on such devices is illegal in some/all states and if anything goes wrong it could impact any insurance claim. BUT in dealing with repair people I find it is always beneficial that you know what is wrong, it can save them time in investigating and reduce your repair costs.

Peter

FollowupID: 537683