Unvented Cylinder showing signs of rust

[juslisnen]

We have a Range tribune unvented cylinder that is showing signs of rust at the bottom. Only just picked up on it. Been in the property 5 years. The property was built 2004/2005. I understand these units have a 25 year guarantee? But wanted to ask should we swap out as a precaution (as they aren’t cheap!!)

Does anyone know how they are constructed? Do they have a mild steel outer casing and stainless steel inner? I.e. are we just seeing rust on what is cosmetic sleeve?
Or is it best just to get it done?

We’ve had an advisory from plumber but just wanted second opinion.

Thanks

 

[ajstoneservices]

The rust is on the outer case and will not cause it to leak as the stainless steel cylinder is encased in that mild steel outer. Mine also has signs of rust but it won't be getting replaced.

 

[Londoner2]

25 guarantee is for the inner steel only i think.

 

[ReJect]

The 25 year warranty only applies if the unit has a yearly service record.
I think on that cylinder the outer insulation case is mild steel, but the inner stainless steel cylinder, or one of the joints must be leaking. If proved to be a fixable joint or fitting leak, then that would be fine just to repair. Inner cylinder not repairable.
It would not cost a lot for new unit (must come complete with new controls).
All work must be carried out by a G3 unvented qualified plumber.
I note that the discharge pipe is incorrect

 

[juslisnen]

Thanks for the quick replies guys.

@ReJect - How would I put this to the plumber who normally does our work (discharge pipe)?
What exactly is the issue, as I'm no plumber

I'm looking at the cost of the cylinders and they range from £500 (Gledhill) to £1000 for the Worcester Bosch/HEatrae Sadia. Are they all the same as far as what they do or can anyone recommend a particular brand (180ltr).

Thanks

Range Tribune 180L

• juslisnen
• 29 Nov 2019

 

[ReJect]

Thanks for the quick replies guys.

@ReJect - How would I put this to the plumber who normally does our work (discharge pipe)?
What exactly is the issue, as I'm no plumber

I'm looking at the cost of the cylinders and they range from £500 (Gledhill) to £1000 for the Worcester Bosch/HEatrae Sadia. Are they all the same as far as what they do or can anyone recommend a particular brand (180ltr).

Thanks

Range Tribune 180L

• juslisnen
• 29 Nov 2019

Discharge pipe D1 is wrong judging by your photo. 600mm maximum to the tundish is standard rule.
Your plumber if G3 qualified and experienced will know and would be able to easily pipe it properly, especially when a new unit is installed.

 

[juslisnen]

Thanks @ReJect
Would it be worth getting the system power flushed when the unit gets replaced, as we had a water softener fitted last year?
(Plumber is suggesting RM Stelflow)

 

[Madrab]

My question is though, where has the water that has rusted the cylinder come from? You can see all the staining on the floor. You need to be careful that there is sufficient support under all that. When that chipboard flooring gets wet through, it becomes very weak.

 

[juslisnen]

My question is though, where has the water that has rusted the cylinder come from? You can see all the staining on the floor. You need to be careful that there is sufficient support under all that. When that chipboard flooring gets wet through, it becomes very weak.

That stain has been there before we arrived. So whatever was leaking was repaired long before we turned up. I will definitely check the flooring Though when plumber rips out existing tank.

 

[Madrab]

Yup, I would hazard a guess that whatever stained the floor also saturated the bottom of the cylinder ergo why it's now rusting from below. If the cylinder's being replaced then I'd be looking at a piece of 22mm WBP Ply to go in there.

 

[dilalio]

Looks to me like the tprv has been leaking and is a "likely candidate" for the resulting rusting at the base. Also shouldn't be an elbow on the discharge, that close to the tprv.