Inspecting a hot water tank for sediment build up.

[FiscoKing]

Hi,

What's the process for inspecting a hot water tank and sediment build up?

Just seen a video of someone cutting open a HW cylinder that was 1/3 full of sediment.

Mine's a Valliant Unistor stainless unvented with expendable anode. Prolly 15+ years old (no date stamp on it).

There's no inspection port like you'd find with a steam boiler and nothing in the installation manual about internal inspections.

Drain the cylinder and remove the hot water element? Poke an inspection camera in? Probably need a new immersion seal after 15+ years. Or poke a camera in from the top HW outlet port?

If no one is checking their cylinders then presumably people just replace them when the capacity lowers & the hot water goes cold too quickly.

And how do you know when the expendable anode has 'expended'?

Just wondering.

Thanks.

 

[Madrab]

Usually draining it gives a good indication, then filling it from the top and draining again after it's all been churned up. Only way to be sure though is to remove it, turn it upside down and flush it. That is more so for gravity fed open vent HW cylinders though and it's usually down to a silted CWSC that's not been kept clean or covered.

Unvented cylinders are fed from the mains that doesn't tend to have a large amount of silt introduced to then build up in the cylinder and if there is then the filter(s) in the Control Group, would normally catch it.

Sacrificial anodes (SA) are a time thing usually. Though that is also prevalent on water type and cylinder material types, steel or glass coated steel . If yours is S/S then it wouldn't usually have a SA give the low propensity for the S/S to corrode

 

[HERTS P&D]

Take out the immersion and have a look.

Andy