Baxi Back boiler - hot water

John_Jizzle

Hi - I posted about this before but after some other info....

I have a Baxi Bermuda back boiler. Up until last week it was working fine (for the piece of rubbish it is).

Now the thing fires up but then turns off about 10 seconds later - meaning the hot water isnt heating. I had a heating engineer have a look at it and he changed the thermostat but this hasnt sorted the problem.

If I put the setting on heating and hot water it works fine, if i put it on heating and hot water for a few mins - then switch to hot water only it also works.

I am going to get him to have another look but anyone have any ideas what else it could be??

I dont know much about it other than its gravity based - water heats up and gets shot up to the big tank upstairs where it is stored.

Thanks

Ben84

There's a valve which controls where the hot water is pumped after going through the boiler. It may send it to the radiators, a heat exchanger inside the hot water tank or through both at the same time. They occasionally get stuck on one setting, or become unable to select one setting, or just do weird things in general. If yours isn't letting the hot water reach the tank, then the boiler will fire up and once it becomes hot the boiler thermostat will turn it off as the heated water isn't going anywhere.

This is my best guess, but you might discover something else is the fault.

southcoastrgi

Ben84 wrote: »

There's a valve which controls where the hot water is pumped after going through the boiler. It may send it to the radiators, a heat exchanger inside the hot water tank or through both at the same time. They occasionally get stuck on one setting, or become unable to select one setting, or just do weird things in general. If yours isn't letting the hot water reach the tank, then the boiler will fire up and once it becomes hot the boiler thermostat will turn it off as the heated water isn't going anywhere.

This is my best guess, but you might discover something else is the fault.

very good explaination of a fully pumped system however the OP said the hot water is gravity therefore he won't have a mid pos valve, i would say it's either an air lock or sludge, but without seeing it it could be a number of probs.

Ben84

southcoastrgi wrote: »

very good explaination of a fully pumped system however the OP said the hot water is gravity therefore he won't have a mid pos valve, i would say it's either an air lock or sludge, but without seeing it it could be a number of probs.

Ok, I didn't realise gravity systems didn't have a valve. How do they choose where to send the hot water?

southcoastrgi

Ben84 wrote: »

Ok, I didn't realise gravity systems didn't have a valve. How do they choose where to send the hot water?

it doesn't on a gravity system you can have hot water without heating (the pump just doesn't turn on) but you can't have heating without hot water as when ever the boiler fires it heats the hot water via gravity circulation (hence the name), & before some cleaver person comes back & says yes sometimes there is a man valve on the return this is certainly not the norm

John_Jizzle

thanks for the advice.

Would it be possible to get rid of the air lock myself - then if that didn't work get the heating guy out?

gas4you

I would check your timer is working correctly first.

What make and model is it?

John_Jizzle

gas4you wrote: »

I would check your timer is working correctly first.

What make and model is it?

sorry only just seen this and at work now. Its a baxi bermuda - not sure on the the exact model.

the timer is working as when I set it on hot water and heating it works fine.

I let all the air out for the radiators and it seems to have sorted (the one in bathroom seemed full of air!

I had a look to see if i could let it out of the boiler/water system part but couldnt find anything that looked like i could let air out of that.... any ideas?

gas4you

No, I meant make and model of the timer.

gibson123

Get it serviced by a good gas engineer, I was looking to replace mine and I was very lucky with one of the engineers I asked to quote me, he said there was nothing wrong with my current heating system that a thorough service would not cure, I explained that I had it serviced every year and he explained that whoever was doing the service it was not being done properly. Anyway several hours later and the years of dust, dog-hair and soot removed, and running perfectly, and in the engineer's opinion better than a lot of these new replacement boilers. Cost just over £100 and the honest chap has now had dozens of recommendations from me and has saved me a fortune.

ed110220

I had a similar experience with my Baxi Bermuda back boiler. The engineer recommended keeping it as he said they are very long-lasting, reliable and inexpensive to maintain.

I think if you don't use a huge amount of gas, those good points outweigh the better efficiency of a modern boiler.