Radiators get hot when running a bath

[Igorian]

Hi

I hope one of you guys can help

My oil powered boiler is a Potterton Statesman Flowsure. When running hot water to the upstairs bath, the flow rate has to be kept extremely low to maintain temperature, literally a trickle. Also, when running a bath, the radiators get EXTREMELY hot (central heating switch to off position). The pressure guage on the boiler is almost at zero also. Downstairs hot water runs ok. There is no external timer or central thermostat. Radiators have thermostatic valves.

Regards

Ig.

 

[Igorian]

Further to the previous fault, the overheat warning light has come on. I switched the boiler off for a while and then tried to pressing the reset button. Warning indicator is illuminated. I'm wondering if it's time for a new boiler? Any suggestions please guys?

 

[oilman]

As this is probably a combi boiler, it's likely the diverter valve is faulty, and/or the plate heat exchanger is scaled up. It may also be a problem with the bath tap.

You don't need a new boiler.

When was it last serviced? by whom? because it sounds like they didn't check the expansion vessel.

You need an engineer.

 

[Igorian]

Hi Oilman

Thanks for the response. I have had an engineer call and he has estimated the repair of the boiler will be around £500 - £600, including parts, labour and service. I personally thinks it's a lot for a repair so I am looking to replace the boiler.

My next question is how to choose. I am restricted to oil and I think I would like to stick with a combi system. Can you provide any hints on makes to look at (or avoid). I have a 3 bedroom semi and the system currently runs all hot water (except the shower) and feeds 8 radiators. The Potterton Stateman boiler is rated at 20-25 KW. I was considering installing a more powerful unit to give a better flow rate.

I'd be interested to hear your thoughts.

Regards

Ig.