Chemical smell from radiator

helen12345

Hi! Hoping someone can help me diagnose this issue...
We have a combi boiler (maybe around 3 years old gets serviced etc) and we had a new bathroom and radiator (the old column style) installed 2-3 years ago. All has been fine until recently. The radiator in the bathroom has always been a very hot one. 

A few weeks ago a bad chemical smell started coming from the bathroom, we noticed this only happened when the heating was on. I bled the radiator and the smell went, then returned again. Turned the radiator off and if the heating was on, no smell. So it seems the radiator is the culprit. Had an engineer out who has took the radiator off, gave it a proper clean out with chemicals etc (he said it was very dirty) and put more inhibitor in the system. The smell is still there. 

Also to add - the valves on the radiator don’t seem to control the level of heat it’s on or off. Would a new rad/valves help?  We can’t understand as this is quite new and has come out of nowhere. no smell anywhere else in the house. 

Jamie Hall

First off, it can't be anything inside the radiator. Like system water, grundge inside, what have you. Radiators are pretty tight that way.

Therefore, it has to be something on, or in the close vicinity of, the radiator which smells when it gets heated. It's not likely to be something in the wall -- although that is possible. Some detective work is needed. Anything get spilled? Painted?

PC7060

Regarding the temperatures control of the radiator, you can replace existing valve with a Thermostatic Radiator Valve (TRV).   This would enable you to adjust max temperature of radiator as desired. 

HVACNUT

It's not the radiator. It's the missing sock.

helen12345

Thanks for the replies. Nothing has been spilled/painted. The entire room is tiled - so hoping not to have to start taking the bathroom apart as the radiator is above the pipe work boxing in (tiled). It’s difficult trying to trouble shoot something when to rule things out like taking up tiles will be very costly. 

PC7060

Adding TRV doesn't require demo; pretty simple operation for experienced hydronics tech.

nicholas bonham-carter

Can see you see any signs of leakage from the pipes under the floor, from below?
Some of the additives to boiler water could be quite smelly.
If you close off the makeup water inlet to the system, for a few days, does the pressure of the system drop?
In some situations, with an incorrectly installed pump, the pressure could rise up to the point of causing a nail hole in a pipe to leak, only when the system is running. The excess hotness of the bathroom must be a clue of some sort.
“Watson, bring me my copy of ‘Pumping Away’’”.—NBC

helen12345

No signs of a leak from the room beneath. You cannot look in the bathroom as all the pipe work is boxed in and tiled. We haven’t noticed a drop or change of any sort in the pressure, it’s a pretty new combi boiler we have so not sure about the pump? 

helen12345

Forgot to mention I closed both valves for a couple of days and didn’t notice a pressure change. I opened up the thermostatic valve only a quarter turn and this did seem to control the temperature and no smell, opened it up a bit more and again fine no smell. Then tonight a bit of that smell again and rad hot (not sure how much the valve was open)...