Towel radiator on secondary system

[dogbower]

Hi

Recently replaced a towel radiator on a secondary system, not sure of model but was a Myson brass one with chrome finish. After 8 months this developed a pin prick, and showed evidence of corrosion.
Sent back to Myson for testing, and after a lot of chasing they say they can find no fault but will refund and offer a small amount for fitting a replacement.

Due to the time Myson were taking and the fact they no longer make a suitable radiator we replaced it with a stainless steel one.
The day after we heard from Myson our client rang to say the new radiator had developed a leak. Went to have a look, pin prick holes all over it, might have been in 3 weeks at the most.

Very large house with 3 other towel warmers running off the same system, all look fine and have been in for years, no discolouration in the hot water.

Any ideas, feel like we must be missing something obvious, cant believe 2 faulty rads, from 2 different suppliers.
Thanks Stuart.

 

[picasso]

You could have stray currents causing the corrosion, can you test for earth leakage ?

 

[doitall]

Like your thinking Picasso and certainly worth checking although, I think the rads would have gone before now assuming they're not piped in plastic.

3 weeks to eat an SS towel rail sounds more like acid, or it was cheap and very nasty.

 

[dogbower]

Not sure about pipes to other rads, but plastic up to the rad in question.
First rad was expensive, second average price.
Surely even a cheap one, if actually made of stainless steel, would last longer than 3 weeks.

 

[doitall]

If the rail is piped in plastic then either the rail is faulty, or you have a major water problem, that should be checked sooner than later.

You are talking the same water you wash in.

Is the water from a well/bore hole or mains.

 

[dogbower]

House is fed off a spring, the coffee the client made us tasted ok
Cant see 2 rads being faulty, different suppliers/ construction.

 

[doitall]

Is there an earth bond on the rad.

I would get the water tested as a matter of urgency.

Can't see why it would eat a brass rail though.

 

[dogbower]

no bond on rad

 

[Onetap]

Dezincification, maybe. Any white deposits on brass valves on the same circuit?

It's chlorine in the water that causes dezincification of brass; I don't know what happened the SS rail, but I've come across SS welds before that failed as a result of chemical corrosion by chlorine compounds.

 

[dogbower]

Some signs of white deposits on circulating pump.
The SS rad has gone not just on the welds but along the pipes themselves.
Surely to effect the rad that quickly, any problems with the water would be very obvious.
Not to mention hazardous to health.

 

[doitall]

If it's spring water you wouldn't have chlorine unless they have a filtration plant.

 

[Norcon]

A towel rail on a DHW system?

Is this post not relevant here or am I missing something?
//www.diynot.com/forums/viewtopic.php?p=2075064#2075064

 

[Onetap]

A towel rail on a DHW system?

Is this post not relevant here or am I missing something?
//www.diynot.com/forums/viewtopic.php?p=2075064#2075064[/QUOTE]

Still relevant.
I wouldn't, but I've had dealings with legionella.
I can't be arsed telling people, they'll get the hump.

 

[doitall]

A towell rail on a secondary circuit is fine provided you use copper or brass, and I assume Stainless steel. It is after all just an extension of the secondary loop, quite common in the good old days.

No reason legionella should be a problem, as that is bred in the storage tank and stagnant water.

 

[dogbower]

Onetap
I bow to your greater knowledge, rad was a replacement not a new install.
Does this help with why the rads are developing holes after a short period of time?