TRV on a heat dump radiator

[hubbabubba]

Can any one advise whether you can fit a TRV on a heat dump radiator.

The system is an open vented system and the radiator which needs replacing is in the bathroom. It is not on the heating curcuit but is fed from the hot water cyclinder and gets hot when the domestic hot water is on but the heating is not.

The reason the rad needs changing is that it has become choked. The entry is at the top and the return is from the bottom.

I have not come across one set up like this before and think that the water must circulate via natural convection to and from the water in the domestic hot water tank. Sort of like a heat dump radiator. Is this right? If not how does the water circulate?

On the radiator front I want to fit a new rad with a TRV with the entry at the bottom. Will this set up work if it is unpumped heat dump?

Not inspected the rest of the system yet, but if there is muck in the rad on a hot water circuit, then surley the water cyclinder and header will be full of muck as well. Any advice.

Cheers for any help.

 

[pipeslice]

Flush or drain the rads would be a good start!!

The bathroom rad is on the coil circuit and possibly on gravity which is why top and bottom entry

If you fit a trv to the heat dump rad and it closes down be prepared for the DUMP

 

[gavinda]

its actually piped like that to allow you to dry towels year round. you'll find it probly also heats when heating on and water off, so it may also be a bypass rad. either way, dont block it off unless you're sure of what you are doing. replacing a rad because the systems blocked suggests you're not.

 

[sambotc]

Hi,

What fuel do you use? If it's gas then do not worry, if it's solid fuel don't even think about a TRV. The reason the flow enters the top is because it is gravity circulating or at least was when it was originally installed, as i imagine your cylinder is.

More detail on boiler and controls would help.

HTH Sam

 

[hubbabubba]

The system is ancient. More than 45 years old. It originally has a coal burning stove with a back boiler. This was swapped about 35 years ago for a floor standing gas boiler which is working fine and by all accounts never broken down. Its been services anually and nothing ever been changed on it. Does not have a brand on it, but could be an Ideal? Having another look in the morning.

Nothing in the way of additive on the heating circuit so no surprise that radiator is suspected as chocked. All rads on heating circuit are hot all over and bled with clean water when I looked it over last weekend. Its just the one rad giving the problem and would not bleed out any air or cold water.

It is controlled by a mechanical timer switch which gives the obvious combinations of heating and DHW. No thermostats either room ones or TRV on the system.

The installation in the bathroom is just as ancient and over the years access to the tanks has been boarded over for cosmetic reasons. All comming off tomorrow to trace the pipework and see what nasties are elsware. The worry I have that as soon as I fetch the rad of to flush. It the rest will fall apart. New rad needed for the bathroom as it just needs a refurb and the current one is mingin.

Any help is great. I need to help an old guy out who is beggining to struggle sorting stuff on his own.

 

[cider]

as mentioned if gas or oil ok to trv it
originally piped as heat leak rad for solid fuel, but as gravity fed still from cylinder primary circit will prob be sludged up and may never work great unless you re pipe it into heating circuit