Baxi 552 BBU - burner re assembly after clean out

[jirams]

I reported on this forum last weekend my success in cleaning out 552 burner and removing lint trapped in filter. This cured a yellow burning flame - very pleased with result EXCEPT:-

I am getting a lot of expansion clicking and ticking now from what I reckon is the burner when cycling on and off. I am never sure just how much to tighten up the 2 nuts which secure the RHS end plate onto the burner outer sleeve. The sleeve sits on dished rims on the end plates and you can go on tightening up the nuts and expanding the ends of outer sleeve until it might get damaged (this version here does not have gaskets). The nuts usually are found loose on well burnt in burners. I am sure the expansion noises are coming from these nuts not being set correct??

Can anyone offer advice please?

 

[Reg Man]

Try backing them off a quater turn. Gives it, a little room to move, because it all heats up at different rates. Normally BBU's used to make ticking noise, because they are not screwed down to a flat base.

 

[Reg Man]

If your not experieced with Back Boiler units (BBU's) then here's a couple of tips, There are a few common faults to look out for. The side walls where the pipes come through should be properly sealed with suitable material (Brick and cement); the space between the chimney and flue liner should be sealed (Rock wool). ie: there shall be only 2 openings, the front chimney opening and the flue. Any other openings can cause products of combustion to get pulled through them. Also the gas and water pipes should be protected against corrosion, especially if the chimney had been used in the past for solid fuel.

 

[Billy Bob Bob]

bear in mind and regman will remember this if he thinks back.....the middle baffle on 552,s used to make the noise you describe so its not uncommon to find them missing the question is was the noise there before you started?

 

[Reg Man]

Thanks Gasman, Memories.

 

[Billy Bob Bob]

no probs Reg man, my career started out with working on nothing but 551,s 401,s and 552,s know them well they are getting less and less but if i put my money on the most populer boiler ever made it would start with Baxi Burmuda

 

[Reg Man]

Me too. Baxi Bermuda was the best. Did'nt like the old Housewarmers and A framed Parkrays.

 

[Billy Bob Bob]

oh no not the hosewarmers

 

[gasmarc]

just been to have a quick survey on one today installed in 1997 so all looked good, I always quote for 2 hours when servicing these from now on, I remember doing one of these years ago in a doctors house and she said once any of that soot gets into your lungs it never comes out

 

[Billy Bob Bob]

2 hours? you are doing it properly gasmarc i do them in 1.5-2hours anyone who can do them quicker should leave the trade