Radiators not hot enough

[Miki]

I have recently moved into a new home and replaced some of the radiators. A couple of them are larger double panels compared to what they originally were. In total, 3 large type 21's, 2 large type 22's and 2 small ones.
It is a regular vented system with a cylinder and tank in loft.

Now it seems the radiators do not get hot enough. They are hot, but compared to where I used to live, the radiators used to get too hot to touch, where as I can touch the new ones comfortably. As a result the rooms takes forever to warm up, and never really reaches the desired temp of 20-21c.

So the most obvious cause to my untrained mind would be the boiler doesn't pack enough power to deal with the new rads. It is an old boiler, possibly 15-20 years old.

But could it be something that could be a quick fix in the short term?
I have bled all the rads, and do so regularly.
I have turned the pump up from 2 to 3. This has helped slightly, but not enough.

Given the cost of moving home etc, I don't really want to replace the boiler right away, so if anyone has any alternative suggestions on how to improve the situation, I would be grateful.

Thanks

 

[CHRISX]

I have recently moved into a new home and replaced some of the radiators. A couple of them are larger double panels compared to what they originally were. In total, 3 large type 21's, 2 large type 22's and 2 small ones.
It is a regular vented system with a cylinder and tank in loft.

Now it seems the radiators do not get hot enough. They are hot, but compared to where I used to live, the radiators used to get too hot to touch, where as I can touch the new ones comfortably. As a result the rooms takes forever to warm up, and never really reaches the desired temp of 20-21c.

So the most obvious cause to my untrained mind would be the boiler doesn't pack enough power to deal with the new rads. It is an old boiler, possibly 15-20 years old.

But could it be something that could be a quick fix in the short term?
I have bled all the rads, and do so regularly.
I have turned the pump up from 2 to 3. This has helped slightly, but not enough.

Given the cost of moving home etc, I don't really want to replace the boiler right away, so if anyone has any alternative suggestions on how to improve the situation, I would be grateful.

Thanks

Hello Miki,

Please don`t be offended by this question:

Have You made sure that the Boiler Thermostat is turned up to the Maximum setting ?

I am sure that You have but `just to make sure`.

I have had people ask me about their Home`s Central Heating not working correctly only to find that the Boiler Thermostat was set to a low temperature which meant that the Radiators were not getting hot enough to heat the Rooms / Home.

IF the Boiler Thermostat is NOT set at the Maximum when You look at it [you might already know] then you will probably have a very easy `Fix` by just turning it up - unless there was a reason why it was turned down.

Regards,

Chris

 

[snowhead]

Assuming it's not the Stat as above.

To prove whether the boiler is undersized try turning off some of the other radiators in the house, effectively diverting all the boiler output to the new ones.

If that doesn't improve the temperature then the pipework to the radiators may be undersized.

How well does the output of the radiators compare to the heatloss calc for the rooms?