2 piece toilet question

[Brie Schmidt]

So we have a 2 piece toilet - it is one of those water saver ones and we hate it! Can we buy a same brand toilet with the same specs and just switch out the top piece?

[Roy N.]

@Brie Schmidt

Generally you cannot add a larger tank to a low flush toilet. Even if it did fit, you would be ill advised to make the substitution as the toilet is designed to be a single system, even if it comes in two pieces.

All toilets are not created equal and even good brands make terrible models. Before you purchase a toilet, especially a low-flush (1.28 usg or less) you should look at the MAP test score.

We put low flush toilets in all our units - unless the waste line is deteriorated cast iron (read: high friction), then we will wait until we upgrade the plumbing. If you stick to units with MAP scores of 800 or 1000, you should have no more problems than with an old 3 or 5 usg toilet.

We acquired a triplex a few years ago with 4-washrooms, all but one of which contained an old 5 gallon toilet. We replaced all of them with dual flush (3.0l/4.8l, 0.8/1.2 usg) model and reduced the water consumption by ~35%. Our plumbing calls did not increase post refit.