So why do I need an expensive Seaward water heater when a £90 one will do?

[Modulation]

My existing one started leaking through internal corrosion on the weld attaching the cold water feed. I had thought it was a leak in the cw feed, but, when I stripped the casing and insulation off the leak was from just beside the weld - its an aluminium tank and I think it has serious internal corrosion even though I've always had a galvanic isolator.
I'm not happy to repair as I think the problem will recur. I've checked different options for new marine calorifiers but they are all ridiculously expensive, especially as I do not want to connect hot water from the engine to the heating coil. All we ever use is shore power to the 1.5kw immersion heater. So I was thinking of getting just a standard 1.5kw 35 litre water storage heater - the kind one often sees in cloakrooms etc. Available on ebay for £90. And fitted with a pressure relief valve in case of overheating and a replaceable anode. Also they are designed to handle mains pressure which is far higher than I get with my Par 2.9 pump!
Or am I going down the wrong path and missing something important

 

[superheat6k]

Go for it. Marine doesn't mean special, if it did no one with any nounce at all would fit an aluminium tank, just things 'marine' have VAT plus HAT (Hamble Added Tax - substitute Hamble for wherever you keep your boat).

 

[vas]

Go for it. Marine doesn't mean special, if it did no one with any nounce at all would fit an aluminium tank, just things 'marine' have VAT plus HAT (Hamble Added Tax - substitute Hamble for wherever you keep your boat).

+1

I'm about to do the same (only 80lt...) price around 120euro. Even if it fails in 5yrs (I very much doubt!) I can afford replacing it for 4-5times before I get up to the marine price...

V.

 

[coopec]

"new marine calorifiers but they are all ridiculously expensive"

My sentiments entirely and as "superheat6K" says anything with the word "Marine" in front of the name doubles the price.

I was using two pot epoxy enamel (very expensive) to paint the internal of the yacht but on the recommendation of the hardware chain I am now using "Rustguard" (an epoxy enamel) at half the price. (My yacht is F/G)

 

[coopec]

The Penguin Calorifier is not cheap

View attachment 56924


Add to that is freight 17 BP and installation kit 60 BP

 

[David2452]

Whatever you decide to buy make absolutely certain that it is designed for an unvented system and has a SWP compatible with your potable pump, domestic models are often suitable only for vented systems.

 

[PCUK]

He already said he's looking at an 'unvented' model otherwise I would agree with you.