Combi boiler advice for 19 rads ?

[pilot1701]

ok , allow me to expand my details , it's a four bed with just two adults at the moment , so we have one kitchen , one utility , one downstairs bathroom with electric shower , one upstairs bathroom with hot supply from immersion tank shower , the on suite will be a electric shower , whilst I think understand what Harvest is saying , that if the shower is going and someone turns on a hot ? tap it wont be able to cope ? is that right Harvest ?

 

[Aire]

whilst I think understand what Harvest is saying , that if the shower is going and someone turns on a hot ? tap it wont be able to cope ? is that right Harvest ?

That's what he's saying yes and if you installed a 28kw combi which gives you around 11 litres a minute then it would be a problem. But a 35kw firebird enviromax has hot water flow rates over 20 litres a minute which is great. If your going to have 2 electric showers and one fed from the boiler then hot water flow won't be an issue for you.

 

[John.g]

That's what he's saying yes and if you installed a 28kw combi which gives you around 11 litres a minute then it would be a problem. But a 35kw firebird enviromax has hot water flow rates over 20 litres a minute which is great. If your going to have 2 electric showers and one fed from the boiler then hot water flow won't be an issue for you.

Grant do a 36 Kw Combi (also a 26KW), both have a 32 litre hot water store, the 36 kw should give a sustained 15 LPM and more if the stored water is "added on", the 26 Kw should give ~ 11 LPM (more if store is taken into account).
In this part of the world the Grant has a better name than the Firebird but I think Firebird have now addressed most of their problems, the SE Firebird was a outstanding boiler.

 

[SimonG]

Don't fit an oil combi for more than one bathroom.

Hounsfield heat only boiler plus rm unvented cylinder if pressures and flow suffice.

 

[SimonG]

Duplicate

 

[Riley]

That's what he's saying yes and if you installed a 28kw combi which gives you around 11 litres a minute then it would be a problem. But a 35kw firebird enviromax has hot water flow rates over 20 litres a minute which is great. If your going to have 2 electric showers and one fed from the boiler then hot water flow won't be an issue for you.

Assuming the mains is up to it

 

[SimonG]

Oil combis do not give a sustained hot water flow, once the heat store is depleted you are fecked.

 

[Rob Foster]

You state you are off the gas main. Now that rings alarm bells in my experience, often the utility dont supply mains water to outling dwellings at pressure AND volume enough to let your combi do the businss hence some high level stored water for high demand periods is essential esp. in the summer when farmers etc. are sucking the main dry.
Have you tested the pressure and the volume ?
Rob Foster aka centralheatking

 

[king of pipes]

Grant is the most popular brand in our neck of the woods, personally i dont do oil but I have fellow installers I pass jobs onto oil combis seem to cause them more problems than a standard heat only boiler and separate hot water cylinder. Kop

 

[SimonG]

You state you are off the gas main. Now that rings alarm bells in my experience, often the utility dont supply mains water to outling dwellings at pressure AND volume enough to let your combi do the businss hence some high level stored water for high demand periods is essential esp. in the summer when farmers etc. are sucking the main dry.
Have you tested the pressure and the volume ?
Rob Foster aka centralheatking

Load of codswallop.

Just because there's no mains gas doesn't mean there's no decent mains water. Yes there are a few spots off of mains water running on springs or bore holes.

In fact there are a lot of places round our way that are running on mains pressure running at up to 10 bar plus.

 

[Rob Foster]

Load of codswallop.

Just because there's no mains gas doesn't mean there's no decent mains water. Yes there are a few spots off of mains water running on springs or bore holes.

In fact there are a lot of places round our way that are running on mains pressure running at up to 10 bar plus.

So its not worth testing domestic mains water pressure and flow before fitting a highflow combi boiler ? I know parts of London are poor but its a test which should always be applied in my opinion
Rob Foster aka centralheatking