Help... Combi Boiler or Unvented system

[SK04]

Hi, just moved into a new house and have a 25 year old heat only boiler, 114ltr hot water cylinder with central heating pump. Noisy and not efficient. It’s a 4 bed house with two bathrooms. Main one has bath and shower and second one has a shower. Flow is 16 litres minute and 2.3 bar pressure. Currently have two shower pumps because of proximity to water tank in the loft.

I’ve had BG round who’ve told me I need to maintain the current set up and that I can’t have a Combi boiler as we won’t be able to use two showers simultaneously or if someone is showering we can’t turn on the dishwasher/run a tap etc. The quote was pretty high to replace boiler, water cyclinder, carry out pipe work. I checked with a plumber who tells me I can have Combi boiler and have two showers running etc. So now I’m completely confused and don’t know who to believe or what to do. Any help and advice would be much appreciated. Thank you.

 

[ShaunCorbs]

Not really recommend at best a storage combi eg Combi with a cylinder built in

Best option is an unvented cylinder and heat only boiler if your cold water system is ok pressure and flow wise

 

[Riley]

Unvented

 

[Scott_D]

The the plumber know you have 16lpm?

 

[SK04]

Hi, yes he does know we have 16lpm. He told me.

 

[SK04]

Not really recommend at best a storage combi eg Combi with a cylinder built in

Best option is an unvented cylinder and heat only boiler if your cold water system is ok pressure and flow wise

Thanks. I had a Combi in my last place which has 2 bathrooms and we could never use both so thought the Combi suggestion was odd

 

[Harvest Fields]

Unvented and system boiler. Please do not make the mistake of putting a combi in.

 

[SK04]

Thanks all. Seems like Combi is a no go.

 

[Aire]

When you open 2 taps in the house now, how's the flow at both outlets?

 

[townfanjon]

System and unvented assuming you have the room

 

[SK04]

Thanks for the responses. I’m told unvented isn’t an option as flow rate is 16lpm. To go unvented means ripping up floor boards to install pipe work and I have an old microbore system which would also all need replacing - again lots of work/expense/disruption. So guess it looks like a I’ll just have to replace the heat only boiler, hot water cylinder and stick with the vented system?

 

[Harvest Fields]

Thanks for the responses. I’m told unvented isn’t an option as flow rate is 16lpm. To go unvented means ripping up floor boards to install pipe work and I have an old microbore system which would also all need replacing - again lots of work/expense/disruption. So guess it looks like a I’ll just have to replace the heat only boiler, hot water cylinder and stick with the vented system?

You could always upgrad the mains at the same time? Just kidding.

 

[Aire]

You could always upgrad the mains at the same time? Just kidding.

You could, or an accumulator. There's always a way to get what you want, only issue is how much your willing to spend.

 

[Riley]

Why do it twice if you’re having the micro ore ripped out?? It won’t take much more to repipe for an unvented. You will not be happy with a combis results

 

[Aire]

Why do it twice if you’re having the micro ore ripped out?? It won’t take much more to repipe for an unvented. You will not be happy with a combis results

I think with op's situation, unless he's going to improve his water flow rate, he should keep the gravity system. 16ltrs a min isn't great and although he won't have any temperature fluctuations, he will get large fluctuations in flow, he certainly won't be able to use 2 showers at once.

 

[SK04]

Why do it twice if you’re having the micro ore ripped out?? It won’t take much more to repipe for an unvented. You will not be happy with a combis results

Hi, I’m not riping out the microbore etc so unvented isn’t doesn’t seem to be an option.

 

[SK04]

I think with op's situation, unless he's going to improve his water flow rate, he should keep the gravity system. 16ltrs a min isn't great and although he won't have any temperature fluctuations, he will get large fluctuations in flow, he certainly won't be able to use 2 showers at once.

Thanks. I think this is the best way to go as well. Not ideal but given how much work it would take to replace the microbore system etc I think this is my only option.

 

[Riley]

If the microbore is working ok then keep it. It would still work with and unvented water system and a heat only boiler?