New Combi Gas Boiler / Shower Question

Jimmycooker

Hi,

I am looking for the highest domestic hot water (DHW) flowrate boiler with lowest central heating (CH) modulation setting.

I want to ensure there is a good powerful shower in my house, but I also want the boiler to cycle as little as possible.

The Vokera Linea One 38HE has everything i need on paper, 1:10 heating modulation (down to 3.8kW) and 15.6 l/h flowrate. These specs kick all the competitions ass.

Unfortunately i've heard the aluminium heat exchangers are dodgy (despite the fact there is a 5 year guarantee).

What kind of flowrate do i need to give a good shower all year round? I have a small flat where someone may use the sink downstairs at the same time as the shower upstairs.

Anyone any suggestions?

Thanks,
James.

DGOBS

What 'dodgy' things have you heard about vokera HE aluminum heat exchangers, I fond the design quite good, and have had little problems with them

Jimmycooker

I've been told they aren't as robust as the stainless steel heat exchangers found in other boilers....

Have you used / installed this boiler? Do you install boilers in Cork City?

jimjimt

Heat exchangers give trouble only because installers do not flush heating systems prior to install.
Also during service expansion vessels are not charged and checked.

The above are the most common causes of death to all heat exchangers.

That applies to stainless steel heat exchangers as well. I have seen stainless steel heat exchangers ruined after 6-8 months because the system was not flushed and cleaned.

sullzz

Have you got a combi boiler fitted at the moment , if not you will need to get your mains supply tested for flow rate with a weir gauge , also you may need to get your gas supply upsized , there is more involved in getting a combi boiler installed than what people think

Jimmycooker

I got a pressure guage and attached it to the outside (mains) tap and I have 3.5 barg.

I want to fit two boilers, one on a totally new installation (granny flat) and one then possibly at the same time / later on the main house. I know there could be issues with this as the existing system is vented pipework.

I've had problems with air filling in the system, possible 'pitching' which led to oxidation in the rads and leaks which meant i had to replace all of them. I want to flush this down well and install a boiler that modulates (to try and fix the pitching problem and stop pipes from creaking so much as they heat up and cool down).

I know i probably wont have enough water flow for 2 combis so will probably end up installing a new water tank in the boiler house when i install the second boiler (where the boilers themselves are going to be located).

IF anyone here is interested in doing the work please contact me. Im struggling to find someone.

Thanks,
James.