Hot water full on to ignite gas

[staylong]

Hi

I live in a small flat that has an old Ideal Sprint combi boiler. Last week I noticed the pressure on the hot tap was very low and it took ages to fill the bath. It heated ok, in fact it was very hot due to the slow flow rate.

Yesterday I noticed that just the opposite is happening. In order for the gas to ignite I have to have the tap on quite a way so that the gas will ignite and as a result the water flow is so much that it wont get hot.

Pressure is just under one bar. I have five radiators that work ok (seperate switch for heating... seems to be fine). Cheked for air in them and thats ok.

Any ideas what has happened.

 

[ChrisR]

Latest problem is probably due to diaphragm needing replacement. Previous problem - if it was slow to come about - is scale in the heat exchanger. Both easy to deal with on this boiler which is simple to work on. All the bits are available and quite cheap.

 

[staylong]

Thanks ChrisR

Do you know how I can get hold of a manual of the unit so I can work on it? Dont want to be taking off the wrong bits etc. I would get a proffesional in but to be frank I am so broke at the moment. Perhaps a quick pencil drawing of what you mean would help: [email protected]

Cheers

 

[sterose]

Thanks ChrisR

Do you know how I can get hold of a manual of the unit so I can work on it? Dont want to be taking off the wrong bits etc. I would get a proffesional in but to be frank I am so broke at the moment. Perhaps a quick pencil drawing of what you mean would help: [email protected]

Cheers

I would suggest you dont do it yourself.

I'm sure by working on this particular component you will not, as someone once said, "blow all four walls of the house down", but it is still risky to work on boilers when you dont know what youre doing.

 

[staylong]

Thanks for the warning Sterose.

Im quite handy though and me thinks reasonable sensible. I will first try and find someone to help or at least get some sort of diagram for this boiler and wont tackle it without.

 

[sterose]

Thanks for the warning Sterose.

Im quite handy though and me thinks reasonable sensible. I will first try and find someone to help or at least get some sort of diagram for this boiler and wont tackle it without.

Fair enough.
I've never actually had to work on my boiler so I cant help you with how to do it - but just be careful.
Because before you know it, you might bug*er the whole boiler, and end up hiring a pro anyway.

 

[galwag]

The first problem is the dhw calorifier which is scaled up and causing poor hw flow, it may also be sufficiently scaled to restrict flow of water thus preventing diaphragm from lifting and operating microswitches on diverter valve.

Secondly it could also be the diverter valve needs overhauling or replacing (look for signs of leaks on valve) or as ChrisR said it may only be the diaphragm in the diverter valve.

These parts, except possibly the diaphragm are not the easiest to change/descale for the average diy person especially on an old ideal sprint.

Get someone who has had previous practical experience on this model of boiler.

 

[marios_kin]

Manuals for boilers are always getting mislaid. My usual source for replacement is to contact the manufacturers through their web site and ask for one. To date I have not been disappointed.

Because before you know it, you might bug*er the whole boiler, and end up hiring a pro anyway

.

and then it will cost (long intake of breathe between tight lips).

 

[staylong]

Thanks everyone.

Last Question..... How much will it cost to have this type of boiler serviced and flushed? ... Ball Park...???

 

[ChrisR]

Get a manual from Ideal. Check forst whether yours is a "75" or a "rapide" - find the GC number on the boiler - somewhere. If you can do small mechanical jobs on a car you can fix this boiler. I recently replaced the secondary heat exchanger, diverter valve and pump on one of these which was 13 yeaars old but had never been used. All the bits are easy to get, and easy to change.
Where are you?

 

[marios_kin]

Last Question..... How much will it cost to have this type of boiler serviced and flushed? ... Ball Park...???

Anywhere from £35 to £150 (any more dont bother) depending wether or not you know a (corgi) plumber working for a firm, who will do pj's (private jobs). Mostly all that will be done is hoover it out to get rid of dead insects and muck.

 

[staylong]

Chris R

Chris I am in Southport Merseyside.

It seems that what you have done is exactly what I need to tackle. I am pretty sure the problem is dirt/scale. I have noticed that the water has been quite milky lately.

The model I have is an SR75. Nothing fancy on it and looks pretty basic. I have written and emailed Ideal without response so still no manual.

If you have one and can scan a few pages for me I would appreciate it.

Cheers.