Mystery green marks on bathroom floor

[TonyS]

Hello to all forum members!

Hope that you could share some of your experience and help me solve a little mystery. Perhaps, the title gave you some hints already, but here's what I have found on my bathroom floor after going away for a week:

So I had a look underneath and here's what I could see:

There was a bit of rust at the bottom of the towel rail, plus some green marks at the radiator valve plastic part.

Two questions, if I may:

• What should I do about the rust?
• What should I do about the green stuff coming from the radiator valve?

I'm not a plumber, but I do have 'engineer' in my job title, so if any of you think that an average DIY Joe could handle this repair, I would appreciate your guidance.

Thank you in advance!

Tony

 

[SimonG]

Verdigris.

 

[Harvest Fields]

New trv probably need mate or it’s from condensation if the rad is in a bathroom.

 

[Welder]

New trv probably need mate or it’s from condensation if the rad is in a bathroom.

Agree with Harvest. New TRV. Looks to me as if its leaking past the valve stem.

The rust is just that. Do you bleed that rad very often? It looks to me as if some drops from bleeding are left on the bottom and have eventually rusted it. TBH, NO steel rad (no matter what you pay for it) is worth thruppence if you're staying in the house.
Get yourself a stainless steel one and a good quality TRV (e.g. Danfoss) and even if it does rust a tiny bit it's easily cleaned away. With a Danfoss valve, when the o-ring around the actuator pins finally fails you unscrew it and install new all without draining down. Ten mins tops.

 

[Harvest Fields]

Agree with Harvest. New TRV. Looks to me as if its leaking past the valve stem.

The rust is just that. Do you bleed that rad very often? It looks to me as if some drops from bleeding are left on the bottom and have eventually rusted it. TBH, NO steel rad (no matter what you pay for it) is worth thruppence if you're staying in the house.
Get yourself a stainless steel one and a good quality TRV (e.g. Danfoss) and even if it does rust a tiny bit it's easily cleaned away. With a Danfoss valve, when the o-ring around the actuator pins finally fails you unscrew it and install new all without draining down. Ten mins tops.

More of an honeywell TRV man myself

 

[SimonG]

Two lockshield valves for me. Hate trvs in the bathroom.

 

[Harvest Fields]

Look nice in chrome

 

[king of pipes]

Replace the trv the one fitted is suregraft from plumbase, as for the towel rail the problem with rust is often contributed to steel swarf from the 1/2" tappings being left in the rail causing it to rust from inside out, my advice you will need to drain down to change the valve do this first, then the towel rail will need to be flushed through with mains cold water via a hose outside, remove the rust spot and treat with a primer and white top coat paint spray car paint from Halfords will do the job then replace the rail once completely dry , you can add a good quality inhibitor to help protect your system from rust directly into the rail I would add 2 litres if you can through the 1/2" thread which is plugged off with the air tap open pour it in slowly replace the plug and close the vent open up the valves top up the system as necessary to 1.2bar then try out the heating job done . Kop

 

[Welder]

Replace the trv the one fitted is suregraft from plumbase, as for the towel rail the problem with rust is often contributed to steel swarf from the 1/2" tappings being left in the rail causing it to rust from inside out, my advice you will need to drain down to change the valve do this first, then the towel rail will need to be flushed through with mains cold water via a hose outside, remove the rust spot and treat with a primer and white top coat paint spray car paint from Halfords will do the job then replace the rail once completely dry , you can add a good quality inhibitor to help protect your system from rust directly into the rail I would add 2 litres if you can through the 1/2" thread which is plugged off with the air tap open pour it in slowly replace the plug and close the vent open up the valves top up the system as necessary to 1.2bar then try out the heating job done . Kop

Bit confused KOP. If it is actually starting to rust from inside out, there is no point whatsoever in doing anything to it apart from binning it! It will beyond saving so money spent would be literally wasted.

In this instance, looking again at the images, it is surface rust (and not much) so, as you suggest, recoverable for a good period.

 

[oz-plumber]

I would clean the rust marks off and keep my eye on them.
It may just be condensation from being in a bathroom that has accumulated at the bottom of the towel warmer.

If the powder coating is cracked and it is true rust - bin it.

Also, I would bin the TRV and use 2 lockshields.

 

[king of pipes]

Bit confused KOP. If it is actually starting to rust from inside out, there is no point whatsoever in doing anything to it apart from binning it! It will beyond saving so money spent would be literally wasted. Agreed Dave but I have had this before the op may not be in a position to replace it in my opinion its salvageable flush out to remove any magnatite then 2 litres of inhibitor couple of hours labour and your sorted . Cheers kop

In this instance, looking again at the images, it is surface rust (and not much) so, as you suggest, recoverable for a good period.

 

[TonyS]

I would like to thank all contributors to the thread: you have provided a plenty of useful advice! I'm really happy that there is such a place like this in the UK web with so many helpful professionals.

I will post pics after the replacement.

Have a great day!