Lochinvar Water Heater - how to descale?

[minesapint]

Hi,

I've had this since new (10 yrs ago) and it's worked without fault. Have replaced the sacrificial anode as and when but have recently noticed that it is kettleing slightly.

Also the amount of hot water produced has suddenly decreased dramatically i.e the amount of hot water from a fully heated tank.

Whilst the kettleing points to limescale I don't see how it can be the cause of the reduction in hot water volume.

I have flushed the unit through using the drain at the bottom, whilst allowing the mains feed to drive the contents out - no sign of sedimentation.

So

1) how do I get rid of any limescale (my model has no access point) - and all the limescale removers that I've looked at are for indirect systems. Can I use these and then flush for a day to ensure total removal or is it a no no.

2) What else could be causing the reduction in hot water?

Cheers

 

[Agile]

It sounds as if there is a significant problem with the volume of hot water.

Then there may be a seperate problem with the kettling.

You dont say if its in a launderette or a hotel or B&B. They are hardly ever found in private houses.

My view is that you need an expert to diagnose the volume problem and then after that is fixed to consider any further treatment required.

You seem to think that you can do it as a DIY job! Thats may not be feesible as you dont have the required skill to find the fault(s).

I also get the impression that you have never had it serviced otherwise you would have called your engineer to it first. Servicing is required to ensure it performs correctly! Its not meant to be optional !

They dont normally get lime scaled and if it has it will probably be related to the fault.

Tony

 

[minesapint]

Hi Agile,

Thanks for your prompt reply. Sorry should have quote the model number - I know that Lochivar make some fairly big water heaters but mine certainly isn't one of those.

It's only a 40 gallon capacity unit and Yes it is in a private house.

Re servicing - as I see it, having read the service instructions, there's nothing that a service does that relates to the internal condition of the cylinder other than to replace the sacrificial anode as and when.

The unit is very basic - just like the big ring on a gas cooker with a large pan of water on the top. Yes I agree, annual servicing would be preferable but I can't see how that would have altered the fact that it's scaled up.

I have been quoted £££'s for a company to come and flush it through with HCL followed by caustic but to be honest it's not a great deal more to get a new unit.

What I'm basically looking for is a chemical that I can use to see if standard descaling will do the trick. My problem has been finding one.

Re - hot water volume, as you say this could be a separate issue - perhaps thermostat.

For now I'm just going to flush it through a few times and monitor it's performance closely.

Cheers

 

[Agile]

The gas settings need to be correct otherwise lime deposition could occur.

Something odd must have happened if the volume of water is not as expected.

Any water treatment is difficult because of the large volume. HCl is cheap so I suppose that is a cheap way to get rid of lime scale.

A magnetic water conditioned might prevent further buildup and possible remove some already there.Most I see are in launderettes or hotels and about 200-600 litres.

Tony

Tony

 

[minesapint]

Thanks for your reply Tony.

I've flushed through a few times and used some descaler (for irons, kettles etc) that has improved but not totally cured the kettling (now a very quiet hiss).

Will monitor for the next week or so and then try HCL if the noise increases.

Re water volume - I assume that the thermostat is the cause - again will monitor.

Cheers for your help

Simon

 

[Agile]

I dont see how the thermostat is the cause of low water volumes although if it was sticking on then it could allow the water to overheat and cause scale deposition.

To prevent scale deposition the water needs to be kept below 65°C !!!

A magnetic water conditioner would usually help that too.

Tony