Choice of new boiler

[michael]

I am a new member of this group,and would like to gain opinion on the best form of replacement for my system which was installed by me in

1965.

My boiler is a Glowworm 85-100,and feeds about 20 radiators controlled by a pump,and an indirect Primatic Cylinder fed by gravity,and with a Drayton cyltron valve next to the cylinder in the 1" return flow.The system still works pretty well,though I do not know how efficient it is now.The only problem I have had in the last few years is that occasionally the gravity feed seems to stop working,which is possibly due to an air lock in the cyltron valve.I have since found out (after

45 yrs!) that Drayton in their literature say that this valve is not suitable for use with Primatic Cylinders,presumably because if the valve shuts off due to build up of sludge,and the boiler thermostat fails,then one could have a dangerous situation-I have a pressure relief valve on the boiler,so do not really understand what would happen.Anyway for the moment,I have asked a plumber to take this valve out(I cannot face these jobs these days and prefer to garden and drink cider!) and hope that this improves the hot water delivery. Half of the radiator taps cannot be moved now,but they are set to give a good distribution of hot radiators around the house so I am not worried.I have thought about flushing the system but have been told that it is not necessary,or that it is difficult with a Primatic Cylinder.So,my system is old and not perfect, is fairly reliable and I could either service it or replace it with a modern condensing boiler system.

My plumber (who is also a neighbour and friend)tells me regularly of his frustration with modern condensing boilers.All of his callouts recently have been blockage of the condensing outlets in the cold weather,and the early condensing boilers are suffering from serious corrosion.He also says that modern condensing boilers are now regarded as 'Appliances' (like refrigerators),with an expected lifetime of order 7yrs,and that some can only be guaranteed if the system if regularly power flushed.Progress????

So,I would be very pleased if users of this Group could advise

(a)Is it possible to use power flushing to clean out an old steel (Stelrad) radiator system which includes a Primatic Cylinder,or does it cause more problems than its worth since the system still works?

(b)If I do go down the new condensing boiler route,is there a preferred system option or boiler manufacturer that has a proven reliability record.

Thanks in advance Michael

[...]

A 45 year old system fitted by yourself, which is probably worth more now as scrap as it was when it was pre-installed materials should be stripped out and given a big send off to the scrappies. or Since it is still in working order, put your house on the market and move to spain with the proceeds and you will never need to bother yourself with gas central heating again.

[Doctor Drivel]

Fit a Remeha Avantaplus combi. Remeha have just bought Baxi. The 39C has a high flowrate. Assuming you a decent main water pressure. Very well made with a stainless steel heat exchanger. A properly fitted combi will not have blocked drain. Fit the outside weather sensor. You will not look back.

[Heliotrope Smith]

You forgot the Dungs gas valve.

--- news://freenews.netfront.net/ - complaints: [e-mail] ---

[John Rumm]

The boiler itself is 65% efficient according to the SEDBUK database. The system as a whole is also going to be fairly poor by modern standards.

There is a potential for cross contamination between the domestic hot water and the CH primary water with a primatic cylinder. Hence you can't use corrosion inhibitors, However you should be able to flush and clean a system before refilling etc without any problem.

A common problem alas - not often helped by poor fitting by many installers. Taking the condensate into an internal drain usually prevents any such problems.

Some condensing boilers were never really designed as such and have had the capability grafted onto them. See the "secondary heat exchanger" section on condensing boilers here:

one designed as such from the outset should eliminate that problem.

They boiler makers often suggest a power flush on installation, but not usually "regular" flushing thereafter (although suitably regular treatment with corrosion inhibitor will be in order).

Its also important to realises that modern boilers (condensing or otherwise) are much more complex beasts than ones like yours, so the failure rates and maintenance requirements can be higher (although hopefully the energy saving ought to be significant enough to compensate!)

I am no expert on these cylinders, but IIUC you can flush the system - but you can't treat with inhibitor after.

You will probably get as many answers as people to that question! Even the "top" brands will have had people who had a poor experience etc.

[Andy Cap]

The major factor though is depreciation, which obliterates any benefit. The sole concentration on efficiency should be investigated by the ASA.

[A.Lee]

Yes, it is possible, but a powerflush is not going to clean out all of the crap in the system. On a 40 year old system, there is going to be a lot of iron oxide in it. This will form in lumps in corners that will not come out when poweflushed, but will eventually come off in small pieces as time goes on.

Get a complete new system. It'll add £1000 onto your new boiler price, but well worth it for a sytem that you know is clean, and will run well.

Worcester-Bosch get recommended a lot. I debated this last year, and in the end went for the cheapest boiler I could get, rather than an expensive one which 'may' last 10 years without a major fault. If it lasts 5 years, then I will be happy. I fitted it myself, so no labour cost.Cost around £350 total. Alan.

[Tim W]

A.Lee wibbled on Wednesday 13 January 2010 09:28

What make did you get Alan?

[A.Lee]

Heatline from B+Q. Around £350 for the boiler, and £30 for the flue. Got an OAP to buy for me, so total was £340ish. Has been in for 15 months now, and hasnt given any problem at all. After inspecting it when putting it in, it is very similar to the Alpha Ocean I took out. Obviously poorly spec'd compared to £800 boilers, but it does what I want it to - it heats up water and rads - we only have 6 rads.

Alan.

[Doctor Drivel]

It has a Dungs gas valve.

[YAPH]

I fitted my own boiler, too, but I value my time even though I wasn't paying myself for it and chose to fit a Worcester-Bosch Greenstar 24i junior boiler, as I do for most of my customers. It seems to me reasonably priced for a well-made and well-supported boiler, which I think (and hope!) it is.

My Specsavers varifocals don't correct for hindsight so I may live to regret it but for various reasons I won't bore you with again[1] Worcester Bosch seem like the best punt around at the moment.

[1] google groups will do that if you want