Two rads do not heat

[frankiebabyjnr]

Two radiators in extension do not get hot. Been flushed through bled etc. Rads balanced in house. They get hot when all other rads off but not roasting to the touch, the minute you turn on any other rads, they go coolish again. Could boiler not be strong enough? If so, would changing all upstairs rads from doubles to singles work? I.e less water to heat.

 

[SimonG]

What size pipes feed the new radiators?
Where were the radiators teed into on the existing system? Were they run back to the main flow and return or just teed off the nearest radiator.
Did a builder do it?

 

[frankiebabyjnr]

What size pipes feed the new radiators?
Where were the radiators teed into on the existing system? Were they run back to the main flow and return or just teed off the nearest radiator.
Did a builder do it?

Bigger pipes feeding the 2 new ones. Probably builder but just bought the house. Would need to pick up carpet and floorboards to see how it's all connected. I will need a decent plumber eh? 🤔. Any idea how much it's likely to cost me??

 

[Ben-gee]

Not enough info to even hazard a guess I’m afraid. As long as everyone in your house is well, get a plumber to come and give you a quote ( or get a couple to).
Good luck.

 

[SimonG]

Sounds like it will need some repiping under the floors.

 

[king of pipes]

Get a professional in for a estimate is the best answer rates differ across the country expect to pay £200 - £300 a day + materials . Kop