Combi Boiler Conversions

Viessmann Combination Boiler Conversion Specialists

Here at Gas Pro Heating Ltd we specialize in Combi boiler conversions from system or Heat only boilers.

When deciding to upgrade to a combi boiler from a conventional system boiler here is what we can offer. Generally you gas boiler may be located in your kitchen, utility room or garage. You will have a hot water cylinder that will be located on the first floor in an airing cupboard or Hot press or ground floor in some situations

The  way a combi works is that it heats water directly from the boiler when an outlet such as a tap/ shower/ or a bath is opened. A hot water storage tank is not required. As per Dublin bye laws, a combi boiler can not be ran from the mains water supply like in the UK, it must have a break tank and a pump to pump Hot and cold supplies.

We recommend, The EPS Multiboost tank which is 345 litre in capacity, this tank replaces the main cold water storage tank that will be located in the attic. The Multiboost tank has a built in submersible pump which is very quiet in operation and has an out put of 3.5 bar pressure which is perfect for showers and baths etc. The multiboost tank boosts the Hot and cold supplies to the property to give pressurized water at all outlets to modernize any system.

We generally recommend relocating the new combi boiler and Home boost tank to the attic, as the existing pipework will already be in place for cold supply to the property and the Hot supply from the Hot press down below, pending on space of course and head height. This generally what we will supply in such installations:

  • Viessmann 30 kw combi boiler
  • Vertical flue and flashing kit for main roof, or if on a gable wall a horizontal flue
  • New stud work to house boiler
  • New flooring from attic ladder to boiler location for future maintenance purposes
  • Magnaclean filter to protect boiler
  • Extra expansion vessel for central heating if required
  • Condense waste pipe from boiler to external drain pipe
  • New 22mm gas supply from the gas meter to new boiler location
  • Eps Multi boost tank 345 ltr with submersible 3.5 bar pump (Quiet in operation and purpose built timber stand)
  • New overflow pipe from tank to protrude externally
  • All associated pipe work for Combi boiler and Multi boost tank
  • New electrical spur isolation switch to power controls and new spur switch to power multiboost tank
  • We generally supply and fit a Google nest thermostat running on Open-Therm protocol to modulate the flow temperature of the boiler as it reaches its target temperature saving on fuel and maximizing efficiency
  • Removal of hot water cylinder in hot press
  • All pipework tidied up to look neat
  • Supply and fit of a small radiator in Hot press for drying clothes
  • Old boiler removed from existing location and flue sealed and cemented 
  • Existing pipework capped in situ and made neat
  • Old electrical controls removed 
  • New installation all commissioned and setup and 10 square earth bonding cable  installed from the fuseboard to the attic to cross bond all pipework for safety.

The Viessmann 30 kw combi boiler will run a main bathroom, kitchen sink and downstairs bathroom sink. If you require a combi boiler that will run up to two showers simultaneously then the boiler of choice would be the Viessmann  111 storage combi. More info on this in the Storage combi section of our site.