need new boiler is it worth changing rads as well?

[moody_gaz]

I need a new combi boiler as the current one is just about knackered. will it be worth changing the radiators as well? The system was put in when the house was built 20yrs ago, and the boiler has been playing up for a number of years losing pressure as well as other problems, so I suppose its had a lot of air in the system over the years.

 

[stevetheplumber]

I need a new combi boiler as the current one is just about knackered. will it be worth changing the radiators as well? The system was put in when the house was built 20yrs ago, and the boiler has been playing up for a number of years losing pressure as well as other problems, so I suppose its had a lot of air in the system over the years.

rads and pipe work should be ok but have it powerflushed and new valves

 

[Puddle]

as steve says make sure all clean but if only 20 years old and in good visual condition no need to replace

What you are going to do is find any leaks and repair,best to do this before you replace boiler,as topping system pressure up all the time is a no,no
you will be replacing new boiler in 3 or 4 years if not sorted

 

[moody_gaz]

the pressure is being lost at the combi thru the drain/overpressure valve, it had been leaking for a good while but now the expansion tank has gone so the boiler is pressuring up and opening the valve every time the CH is on. I only wondered about the rads as I had read in some forum that the radiators should be changed every 25 years anyway.

 

[radswilldo]

Did the rads originally have inhibitor, if it did chances are some one drained it out.You've already mentioned about loosing pressure, every refill adds fresh oxygen cuasing incresed corrosion. Sludge can be removed but you cannot reverse the damage, fillaments of metal can still break off after a flush and cause damage, pump etc. There is also scale build up to take into account, this effects thermal efficiency which in turn effects fuel efficiencey. Rads over 25 years go in my van to the scrap yard, between that and 15 years it depends on how they've been treated and maintained. You need a proffesional to look and give advice, also get one estimate for boiler only and one with rads, it will not hurt.

 

[moody_gaz]

I've been in here for the last ten years. I had the rads flushed about eight years ago cause the rads were not getting hot enough, I can't remember him putting in any inhibitor after though. If I do buy more rads is it better to overspec or just go with the results of the BTU calculator?

 

[Puddle]

Oversizing within reason is good
As it allows boiler to condensate for longer,operate at lower temp and has better heat loss achieved through radiators thus increases efficencey,thermostatic valves will allow air temp control of each radiated area