TRV problems?

[joytim]

Hi

I have looked at other posts but can't find anything this obvious!

Apologies, but this question may be far too obvious, however I have moved into a new house which has TRV on all rads. My combi boiler is a Worcester 350 and when I put the heating on they all heat up nicely.

However, once they reach a certain temperature, they start to go cool (some even go stone cold) before heating up again. Our house isn't the warmest so we end up having fairly severe fluctuating room temperatures in some rooms.

I then put all TRVs on full thinking that this would mean all radiators got hot, and stayed hot. However the fluctuation still occurs.

Q: Is this how normal TRVs work. Other people we know don't seem to get the hot/cold/hot situation. Or do we have cheap TRVs?

The TRVs have "acl lifestyle" written on them if it helps.

Many thanks

Tim

 

[corgiman]

do you have a room thermostat?

 

[joytim]

Thanks for the quick response Corgiman... No, we don't have any room thermostats.

Tim

 

[Softus]

joytim, what do you think happens when the TRVs all reach temperature and shut off?

 

[joytim]

To be honest, I simply think that the TRVs are doing their job i.e. letting the rads get to a certain temperature, then shutting, then starting up again. My only suprise is that I would have expected the rads to get to temp, then cool very slightly, then start up again; whereas in reality they seem to cool quite a lot before starting up again.

It also appears as though the boiler heats up, then the burners stop, and then start again... so maybe it is the boiler, not the TRVs? I just assumed the boiler stopped heating because all the rads had reached full temp.

 

[Softus]

To be honest, I simply think that the TRVs are doing their job i.e. letting the rads get to a certain temperature, then shutting, then starting up again.

I'm pretty sure that this is what they are doing, but if water isn't being heated and pumped, then no amount of opening by a TRV is going to make the rad hotter.

It also appears as though the boiler heats up, then the burners stop, and then start again... so maybe it is the boiler, not the TRVs? I just assumed the boiler stopped heating because all the rads had reached full temp.

Wrong assumption. If you have no room stat then the boiler stops heating when the boiler reaches its full temperature. Depending on the pump overrun arrangement, the boiler might take a long time to cool down enough to start up again.

I haven't checked, but I would expect your boiler manufacturer to stipulate the installation of a bypass when all rads have TRVs. Do you have one?

Is there any particular reason why you have TRVs and no room stat?

 

[bengasman]

Take the heads of the trvs and see what happens

 

[joytim]

Thanks for the information guys. Softus - as to why I don't have a room thermostat, I don't know as I only moved into thew house just over a month ago so am trying to get to grips with its idiosyncrasies!

I'll try taking the heads off all the TRVs to see what happens. Presumably if the "problem" continues, it is boiler-related, not TRV -related.

I have a Worcester-Bosch 350, but who knows who has put it in, or how.

Cheers

Tim

 

[D_Hailsham]

What make TRVs do you have?

Your problem is typical of systems with TRVs which have not been balanced properly.

 

[Softus]

As well as the TRV make, could you tell us the colour of your carpet and the size of your front door - it could be important.

 

[xild]

Softus,That sounds a little harsh Mate, i'm new here but it sounds like the guy is at least on the ball!

Take the heads off the stats, if all the rooms get warm and the boiler comes on goes off and then comes on again, etc, and maintains a reasonably constant temperature, you just have crap valves.
Fit a good quality Programmable room thermostat and balance the system using the lockshield valves on the other side of the rads.

 

[Softus]

Softus,That sounds a little harsh Mate, i'm new here but it sounds like the guy is at least on the ball!

Who do you think my comment was aimed at, xild?

Fit a good quality Programmable room thermostat and balance the system using the lockshield valves on the other side of the rads.

I'm curious - why would you balance the rads if they have TRVs?

 

[xild]

I think your comments were aimed at Joytim.
If you take the heads off TRV's they don't wotk and the system needs balancing.

 

[D_Hailsham]

I'm curious - why would you balance the rads if they have TRVs?

Because if you don't the TRVs will not work properly.

Read and Learn:

Drayton Commissioning Instructions

 

[xild]

Actually they won't work at all!