boiler overheating

My Keston C36 combi boiler is acting up - the water's getting way too hot. It's hitting around 90 degrees when in use. And then bounces back to 40s. The led indicator for DHW also turns ON/OFF while temperatures bounces. (PFA) Any ideas what might be causing this or how I can fix it? To add...

This error code appears daily when the shower is in use in main bathroom (and abruptly stops hot water) It works fine if I use shower in second (ensuite) bathroom. On the website it says "E03: Overheated boiler". (It might be true as the water in main bathroom comes out real hot! Even if I...

Yesterday I was painting my kitchen, we have push-fit plumbing so I decided to remove my radiator to get behind the pipes and the radiator. I drained the central heating system, but forgot to switch the boiler off. Afterwards, when I put the radiator back, re-pressurised the system, bled the...

Hi hoping someone can help... I have a valliant ecotech plus 637 installed in a refurbished property. The boiler will not heat the radiators as it keeps cycling to code S.07 pump overrun as the temperature shown on the boiler display rises from 40degrees c to 80 in the space of a few minutes...

Hi, A strange fault has developed over the last week or so in our Worcester Bosch 40CDi (conventional) based central heating/hot water system. Several times over the last week or so there has been load banging coming from the boiler when it first fires up in the morning. I was able to see what...