Ready to hire?

Post your job in minutes, browse real reviews and choose who to speak to.Post a job

Need some tips or advice?

Plumbing

Problems with new combi boiler after install - is a mains booster pump the solution?

Anonymous user 03/03/2024 - 3.27 PM

I have a 3rd storey apartment and was experiencing issues with the combi boiler. I was told by the plumber to replace the boiler so, on his advice, I did, and now there are still two problems. 1: low flow rate in the shower. 2: heating circuit loses pressure. Error 118 on Baxi boiler. I have been told that installing a Salamander booster pump will solve these issues, but I am very skeptical. Here are a few other points: - The water pressure varies considerably during the day, worst in the morning - Other flats in the block do not seem to have a problem - The supply from the mains is split between multiple properties but each have their own meter - I have a mixer shower in the bathroom and one plumber has advised me to replace it instead of installing a booster pump - I live in a hard water area - The plumber who installed the pump says that there are no leaks in the central heating system and the loss of pressure is due to a firing sequence? I find this hard to believe because where is the water used to fill it going? I do not want to pay for a booster pump if it is not going to solve the problem. Due to the extreme losses of pressure at certain times of the day, I am wondering whether other properties on the supply are taking the available pressure from the network branch. Is there anyway to prove this? And even if I fix the issue of the low flow in the shower by boosting the mains pressure, then how is a booster pump going to fix the second problem of dropping mains pressure in the heating circuit?

Are you a tradesperson and able to answer this question?

4 Answers

D & R Property and Plumbing Maintenance

Rating: 4.9 out of 5

New Romney

baxi error 118 low pressure you have a leak,prv letting by,expansion vessel problem,or expansion vessel capacity to small,water pressure will be worse in morning every one else is using it,how do you know other flats do not have this problem ?,booster pump may give you higher pressure but no higher volume,it may also cause problems for other users of split main.

Answered13 February 2020

Luca Dimaria

No reviews yet

Coulsdon

I agree with the other answer. It's possible the boiler could have a split heat exchanger but as it's new that would be unlikely. If the PRV is letting by you should be able to find where it terminates (on an outside wall) and see if it's dripping. The expansion vessel could just need recharging. The shower could simply have blocked filters.

Answered13 February 2020

Edward Bagg

Rating: 5 out of 5

Newcastle Upon Tyne

You should install the right boiler for your area mains pressure and the amount of rooms you want it to serve. Anything else is unlikely to work very well.

Answered14 February 2020

Think Maintenance!

No reviews yet

Norwich

As I do not know what the original problem for the boiler swap I will answer on what has been said 1 mains pressure shouldn`t really change due to demand 2 The problem is only evident in the shower which indicates that the shower is scaled up affecting flow and temperature 3 if there is poor flow rate over the entire property then I would say the boiler has been incorrectly sized (need more detail) In terms of pressure loss ( expansion vessel needs recharging as is a new boiler. However, if the system was not cleaned properly then the expansion vessel could have sustained damage, This can be checked very easily. The price will probably be lifting because there is dirt on the seat which requires cleaning off. In terms of under-sizing of the expansion vessel, this would not be relevant in this case because of the size of the property! As for the booster pump not on a sealed system which this is! without looking this would be the closest diagnosis which I can make.

Answered21 February 2020