New Boiler

[Chrispy2]

Hello,

I have had a couple of quotes for a new combi boiler recently which have varied wildly!

A company called DGI have quoted £2350 to install a new combi boiler and flue in our loft, with new thermostat. The boiler is a Potterton Promax 24HE.

Southern Electric offered a Worcester Greenstar 25si with wireless thermostat, again in the loft for just over £3000.

British Gas offered a Worcester Greenstar 28i for nearly £3700.

I know very little of boilers and central heating in general, but am trying to get clued up.

The Southern Electric chap was the only one to do flow rate tests, which surprised me.

Current Hot Water Flow Rate is 5 litres per minute

Cold Water is about 17.5-20 litres per minute.

Seems to me from this alone that the Worcester Greenstar 28i is a silly pick as it has a Hot Water Flow Rate of 11.4, more than we would need/make use of.

We have a 3 bed semi-detached with one bathroom. Our current boiler is a 16-20 year old Worcester and is playing up big style unsurprisngly - pump I think. So we are taking the opportunity to get it replaced and moved into the loft from it's current location in the bathroom cupboard (which we hope to one day turn into a walk-in shower). There are only two of us in the house, though that may increase in the boiler's lifetime.

Really appreciate any help/advice. The quotes vary so much and both BG and SE chaps heavily slated Potterton. My M&D have one though and have had no problems, although it's not a combi, but a boiler and hot water tank job.

Thanks,

Chris

 

[Chrispy2]

We currently have 7 radiators, but will be increasing to 8 soon hopefully, one small one for the conservatory to take the edge off and save the furniture from frost.

 

[flameport]

British Gas prices will always be far more than anyone else, so ignore that one.
Same probably applies to southern electric. These companies rely on customers who still think of these companies as the 'gas board' where all gas items must come from no matter what the price is.

A radiator in a conservatory won't comply with building regulations.

 

[kevindgas]

not put that boiler in, but have put in a few gold's and a few performa's none so far have let me down. potterton/baxi are good reliable boilers for the money in my opinion and would not hessitate to fit them.
as for price my price would be similar to the dgi quote
BG won't recommend potterton as they are in bed with worcester bosch! if you liked the guy from dgi i would ask locally about them and consider the local knowledge.

 

[Agile]

I can beat all those quotes. Contact me via my profile if interested.

Is work so scarce in Humberside that you can travel to Gloucestershire to fit boilers?

 

[dcawkwell]

I can beat all those quotes. Contact me via my profile if interested.

Is work so scarce in Humberside that you can travel to Gloucestershire to fit boilers?

Too right.

 

[muggles]

Ask your friends/neighbours for the names of the installers they use and would recommend, then get a couple of quotes from them. Certainly your SE and BG quotes seem high, but I'd expect them to be.

As has been mentioned, you can't put a radiator in your conservatory.

Your current low hot water flow rate may well be due to a blocked/scaled heat exchanger, which is fairly simple to fix.

 

[Agile]

Thats a good point.

Why do you want to change yor current boiler?

All combis give a minimum of 9 litres per minute of hot water subject to the available flow rate from the mains.

Its the dynamic flow rate which is relevant rather than open pipe which is only a guide to the possible performance.

What Worcester model do you have and what efforts have you made to get it serviced/repaired to work correctly?

Tony

 

[Rob_Quads]

I would call a few local traders and get them quoting. At least 3 local ones to get a good idea. I have just gone through the same and got 3 of which 1 was way out and so got a 4th round. It was the 4th who i then went with.

CheckATrade is also very good for seeing local traders who have had good feedback.

 

[Whitespirit66]

Current Hot Water Flow Rate is 5 litres per minute

Cold Water is about 17.5-20 litres per minute.

Seems to me from this alone that the Worcester Greenstar 28i is a silly pick as it has a Hot Water Flow Rate of 11.4, more than we would need/make use of.

You seem to have misunderstood the info re. flow rates. Your current boiler has a max. of 20 L/M of cold going into it, but because it has faults, it is slowing the flow down to give a hot flow output of 5 L/M. The current low hot flow rate of your current boiler is irrelevant as you will be replacing it.

You have a maimum of 20 l/M cold flow, which would be slowed to 11.4 L/M of hot output at the tap if you had the Worcester. All combis slow the cold, so that they are able to heat the water as it passes through the boiler. What's important, is that the cold flow rate is higher than a boiler's hot output flow rate, if you want the boiler to give maximum capacity. You have excellent flow, and will be sufficient for most combis on the market.

Get a local recommended installer, and make sure the heating system is properly cleaned to minimise future problems.

 

[Chrispy2]

Oh god, numpty moment.

Cold water flow rate is half that quoted. It is actually somewhere between 8.75 and 10 litres per minute. My bad. Takes about 3.5 seconds to fill half a litre jug, forgot the divide by two bit!

It's reassuring to hear your thoughts. Do the building regs prohibit having a rad off of the main CH system now then? That's a buggar if so!

We want to replace the current boiler as we don't want to spend money fixing it when we ultimately want to move it out of the bathroom to fit a walk-in shower in. Plus the current boiler, at about 20 years old is not particularly efficient.

I will get in touch with a local plumber and see what he comes up with as an alternative. DGI are the contractors for Glos County Council so I would think they are reasonably reputable.