Ideal Classic only heating to 35-40 c

[awg294]

HI, new to the forum here, please can anyone help me solve my heating problem:

House - 3 bed semi
Boiler - Ideal Classic 250 FF, approx 14 years old I think (came with the house!)
(Standard vented system with F & E in loft and hot water tank in airing cupboard, boiler on the wall under the stairs.)
7 Rads in total, all new, replaced with all new valves, new 3 way valve and new pump 12 months ago last winter.

Boiler has been kettling and whining this winter, and the rads only lukewarm approx 35 degrees. Also can hear air in system pipes but none in rads.

I've just run DS40 through it for a few days and cleared a load of scale from the expansion tank (and drained and refilled) as I had thought it was the boiler scaled up. The flow seems pretty good round the system with an even temp achievable throughout and no cold or hot spots.

Kettling has improved but still a little bit at times.Boiler is still only heating the rads up to 35 degrees C, and the exit pipe from the boiler only reaches 40% when all the rads are on, but it did reach 60 for a short while yesterday when only one rad is on (boiler thermostat contoller is set to max).

I find that when I try and balance the system I can do the upstairs 4 rads ok and got a temp in the high 50s initially, but once I start switching on the downstairs rads the whole system drops to the mid 30s. I now also get a hissing sound from some rads where they are throttled back.

Can anyone please advise a way forward please?

Thanks, Al.

PS I should add I seem to get a lot of air that is hard to expel after draining - it only has one vent which is on the HW intake - should I fit one to the heating flow too? Or should it be adequate that it vents to the F & E tank? - just worried there's a lot of air bubbles stuck in it.

 

[gas112]

Does your system have an air seperator fitted. This will be between the boiler and pump

 

[awg294]

hi, thanks but no it doesn;t have one of those.

 

[Agile]

DS40 is not very good on scale.

X200 is better and can be left in the system.

However, I am wondering if a gas setting is at fault. When was it last properly serviced?

Tony

 

[awg294]

Thanks Tony; chuffed you replied as I'd learnt a lot from reading some of your posts beforehand - understand the DS3 is better but I can't get enough temperature to make it effective, so that was why I went for the DS40 thinking it might be next best. It did shift some judging by the contents of the F & E after a few days, but probably more to come.

I hadn't considered x200 as thought it was just a noise reducer, but worth a try as I guess all noise reducers shift scale - will give that a try in the morning.

I had been considering X800 - or is that only any use with a powerflusher???

It is due a service as it was probably 18 or more months ago when it had a fan replacement.

Monitored boiler today - and have found I can get 60 degrees when only the HW is on or when only one or two rads are on, but that then drops to 40-45 when everything is on.

Have also observed some magnetic pull on the pipes around the pump, so am also wondering if my flow is a bit restricted? And if a powerlush is worth doing too?

Thanks alot, any further clues much appreciated.

 

[45yearsagasman]

Have also observed some magnetic pull on the pipes around the pump, so am also wondering if my flow is a bit restricted? And if a powerlush is worth doing too?

Hard deposits like you have detected will not be removed by powerflushing. The affected pipe needs cutting out and physically cleaning or replacing.

 

[Agile]

I think the kettling is a red herring!

Your problem is a lack of input power. That involves gas settings and the only advice we can give is to get a registered gas engineer.

A small check you can make is to turn on three gas burners on your cooker and see if the flame reduces in size when the boiler is turned on.

Tony