frost stat on boiler

matty_hunt

Hi. Im installing a combi in the loft, on the gable end wall. Do I need a frost stat on the boiler for this location? My choices are Biasi riva 28he (£505)with frost stat or the cheaper Biasi Garda 28he (£420)without frost stat. I cant see any other difference in these two boilers other than the frost stat. Are these boilers an ok choice?

Thanks

EliteHeat

No, they are both absolute rubbish. This is a case of less is less.

If you want a frost stat - and why wouldn't you - why not just buy one?

matty_hunt

EliteHeat wrote: »

both absolute rubbish.

So what is good for a 2bed EoT with nice flow rate at a lowish price? Or, what sort of price range do I need to be looking at before cheaper becomes false economy?

EliteHeat

matty_hunt wrote: »

So what is good for a 2bed EoT with nice flow rate at a lowish price? Or, what sort of price range do I need to be looking at before cheaper becomes false economy?

As a rule of thumb, anything that you can buy at B&Q is not worth installing. Have you ever seen any real heating engineers sourcing their gear at such places?

If you can answer the following, I will be happy to help:-

1) What is your dynamic water flow rate
2) What is your dynamic water pressure
3) What are both of the above measured in the loft
4) Where is your gas meter

matty_hunt

thanks for the response. Q1-3 I cant answer only to say that when the water board installed the meter he said I have very good mains pressure. The gas meter is outside the front door, boiler currently next to back door tho relocating into loft.

EliteHeat

Well take your pick then, it all depends on how much hot water you want.

If I were in a budget I would go for a Main which is the same as a Baxi or Potterton but has a different badge on it. These are "B" rated boilers and are either (1) old hat or (2) proven technology depending on your viewpoint.

Next of the budget boilers would be an Ariston.

If I wanted to spend a bit more I would buy a Vaillant or a Worcester Bosch.

If I wanted to take a bit of a risk, I might chance a Heatline HE which, although made in Turkey, shares all of its main components with more expensive boilers.

I would not, under any circumstances, ever fit a Biasi although I am sure that there are millions of satisfied customers who swear by them - and probably have a Yugo on the drive.

matty_hunt

interesting. thanks. flow rate is an issue. Ive no experience of a combi so whilst the difference between 9.8l/m 10.1 or 11.7 maybe high in percentages but in real terms, is it noticable? I guess the higher the better but is there any real difference in 9.8 to 10.1?
thanks

EliteHeat

The flow rates are expressed in terms of a temperature rise of 35 degrees. So, a 24kW boiler is capable of raising 15 degrees to 50 degrees at 9.8 litres per minute.

This might sound quite impressive, but what happens in the winter when the temperature plummets? the boilers performance will be severely degraded, running a bath could take 25-30 minutes.

As a minimum I would fit a 30kW - the difference between 9.8 and 12.2 litres is noticeable.