CH Issue on new system

[cr0ft]

So your expansion should be 12l about what size is fitted ?

And the copper would just soak up some of the expansion eg by growing

You know, I reckon you are on to something The one in the boiler is an 8L vessel. I have an expansion vessel at our unit and can pop over and fit one next week.

Might be a bit of an own goal this one. I always just assumed that the one in system boilers would be sufficient for a 3/4 bedroom house tbh.

If you are right then I owe you a beer and I've learned something new!

Thanks.

 

[ShaunCorbs]

You know, I reckon you are on to something The one in the boiler is an 8L vessel. I have an expansion vessel at our unit and can pop over and fit one next week.

Might be a bit of an own goal this one. I always just assumed that the one in system boilers would be sufficient for a 3/4 bedroom house tbh.

If you are right then I owe you a beer and I've learned something new!

Thanks.

Now this is where it gets fun I always remove the internal vessel and fit an external one if undersized, I've seen some that just add let's say an extra 4l one which I think is a bit naff,

But tbh you will be surprised how many are undersized/ not thought about especially on combi boilers on big rad systems

Rule of thumb 1 rad 1l of expansion

 

[cr0ft]

Got you. Do you think that it being undersized will cause all of the copper pipes to creak then?? When I unclipped a 3m section of 22mm flow and return pipework under the hallway floor I actually saw it jump up off the joists about 5mm. Seems too much to be thermal expansion to me. Could well be expansion due to pressure increase I guess.

2 of the rads downstairs are large double rads too so I guess in reality that's 14 rads really.

I just always assumed that if it was too small it would spike to 3 bars and vent from the PRV.

 

[ShaunCorbs]

Got you. Do you think that it being undersized will cause all of the copper pipes to creak then?? When I unclipped a 3m section of 22mm flow and return pipework under the hallway floor I actually saw it jump up off the joists about 5mm. Seems too much to be thermal expansion to me. Could well be expansion due to pressure increase I guess.

2 of the rads downstairs are large double rads too so I guess in reality that's 14 rads really.

I just always assumed that if it was too small it would spike to 3 bars and vent from the PRV.

And if you have the length would expand in the copper

 

[cr0ft]

Yeah I'm going to go with that too tbh. It's not a massive heating circuit but it's certainly bigger than your normal domestic system. The noises are all around the house wherever there is copper pipework so it's got to be that I think.

Will update next week, thanks!

 

[ShaunCorbs]

Yeah I'm going to go with that too tbh. It's not a massive heating circuit but it's certainly bigger than your normal domestic system. The noises are all around the house wherever there is copper pipework so it's got to be that I think.

Will update next week, thanks!

And thank you for still using copper most these days use plastic for speed and low thermal expansion

 

[cr0ft]

I hate plastic pipework with a passion and will only fit it if the customer insists.

 

[kb76]

Could you shut a few rads of to reduce system volume from cold. Fire up and see if it makes a difference? Just a thought however it does sound like extra expansion is needed

 

[cr0ft]

Yeah I could tbh but from checking up the expansion vessel is definitely undersized. Easy job to shut off the return under the boiler and the magnaclean and fit an expansion vessel in between the two of them.

 

[cr0ft]

So went back and fitted an additional 12L expansion vessel today. Pipes are still clicking away when the system warms up. Have pretty much said there's not much I can do about it and it's just normal thermal expansion tbh.

 

[turnpin]

Shame after all that work Kieron but thanks for the update think many others may have fobbed off the custard to be honest...regards Turnpin

 

[cr0ft]

Has anyone ever fitted Copper pipe expansion joints before?? Thinking of putting a couple in on the longer pipe runs on the system.

Copper Expansion Bellows

 

[ShaunCorbs]

Yea fitted a few but only on long runs 25m upwards

 

[Best]

Pipes IMO shouldn't be clipped everywhere. I have never agreed with clips fitted on all pipe runs where they prevent movement - like where a pipe run turns and has no movement both ends. They need some room for thermal expansion.
On fairly long heating pipe runs I was taught to double bend pipe using a bending machine to bend the pipes at 90 degrees and for a metre or two at least to next bend to alter the line of run. Designing the system pipes that way gives the run 2 points of expansion at that area alone.
I would wonder is there a fault inside the boiler though?