Increasing the Radiator Temp

[Gramps]

OK I have had all my radiators off and flushed them out and what a mess they where.I've ran the system for 5 weeks with sludge remover in.Drained it off with no sign of sludge and replaced my old pump,Wilo

50 with Grundfoss 16-50.Noticed that 3 of the rads flow was through the LSV so I have replaced all of my TRV with bidirectional ones and set them accordingly.I've balanced the system as best I can and have got all the rads to about the same temp.Pump is set on speed 2. The thing is the rads are hot but don't really warm the room up and I now have one rad that needs bleeding at least once a week.I've still got fernox superconcentrate to put in and I could turn the pump speed up but is this the answer. Any help would be appreciated

[Harry Bloomfield]

Gramps formulated the question :

Well if they are hot, they are hot - you cannot really expect much more than that. Having to bleed regularly after refilling for a while is normal, its is just the dissolved air coming out of the water. The quantity of air should gradually decline over time.

Running with too high a flow from the pup could actually draw air in, if it is not a sealed system.

[DIY]

The water temp should be about 65 degrees going in and about 50 to 55 degrees going out of each rad. I think that 65 degrees is about as hot as you can get on the supply side. You say that you balanced the system as best you can, did you use an infrared thermometer?

[Gramps]

No I didn't use a thermometer,they all feel(by touch)about the same temp.It is really wether there is any thing more I can do.Would investing in a infared thermometer make much difference.Increasing the pump speed according to Harry might add more air to the system.There is a little bit more I can turn up the boiler temp or should I be happy with at least all my rads are "hot" and just add the fernox. Thanks Brian

[DIY]

Sounds like guesswork to me. The only way of knowing for sure whether the radiators are balanced is to use a thermometer. I used one of these:

[meow2222]

The thermostat on the boiler controls water circulating temp. Balancing rads is not about getting rad temps equal, but about getting room temps equal. Those are easy to measure. (Or unequal if you want.)

NT

[Ed Sirett]

Sorry to disagree the purpose of balancing IS to make the radiators all more or less the same temperature. It's the purpose of the TRVs to prevent rooms form getting over heated. So that they are at the required temp which may or may not be the same temp in each room.